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Petersen-Jones SM, Komáromy AM. Canine and Feline Models of Inherited Retinal Diseases. Cold Spring Harb Perspect Med 2024; 14:a041286. [PMID: 37217283 PMCID: PMC10835616 DOI: 10.1101/cshperspect.a041286] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Naturally occurring inherited retinal diseases (IRDs) in cats and dogs provide a rich source of potential models for human IRDs. In many cases, the phenotypes between the species with mutations of the homologous genes are very similar. Both cats and dogs have a high-acuity retinal region, the area centralis, an equivalent to the human macula, with tightly packed photoreceptors and higher cone density. This and the similarity in globe size to that of humans means these large animal models provide information not obtainable from rodent models. The established cat and dog models include those for Leber congenital amaurosis, retinitis pigmentosa (including recessive, dominant, and X-linked forms), achromatopsia, Best disease, congenital stationary night blindness and other synaptic dysfunctions, RDH5-associated retinopathy, and Stargardt disease. Several of these models have proven to be important in the development of translational therapies such as gene-augmentation therapies. Advances have been made in editing the canine genome, which necessitated overcoming challenges presented by the specifics of canine reproduction. Feline genome editing presents fewer challenges. We can anticipate the generation of specific cat and dog IRD models by genome editing in the future.
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Affiliation(s)
- Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan 48824, USA
| | - András M Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan 48824, USA
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2
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Schall PZ, Winkler PA, Petersen-Jones SM, Yuzbasiyan-Gurkan V, Kidd JM. Genome-wide methylation patterns from canine nanopore assemblies. G3 (BETHESDA, MD.) 2023; 13:jkad203. [PMID: 37681359 PMCID: PMC10627269 DOI: 10.1093/g3journal/jkad203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 08/23/2023] [Accepted: 08/29/2023] [Indexed: 09/09/2023]
Abstract
Recent advances in long-read sequencing have enabled the creation of reference-quality genome assemblies for multiple individuals within a species. In particular, 8 long-read genome assemblies have recently been published for the canine model (dogs and wolves). These assemblies were created using a range of sequencing and computational approaches, with only limited comparisons described among subsets of the assemblies. Here we present 3 high-quality de novo reference assemblies based upon Oxford Nanopore long-read sequencing: 2 Bernese Mountain Dogs (BD & OD) and a Cairn terrier (CA611). These breeds are of particular interest due to the enrichment of unresolved genetic disorders. Leveraging advancement in software technologies, we utilized published data of Labrador Retriever (Yella) to generate a new assembly, resulting in a ∼280-fold increase in continuity (N50 size of 91 kbp vs 25.75 Mbp). In conjunction with these 4 new assemblies, we uniformly assessed 8 existing assemblies for generalized quality metrics, sequence divergence, and a detailed BUSCO assessment. We identified a set of ∼400 conserved genes during the BUSCO analysis missing in all assemblies. Genome-wide methylation profiles were generated from the nanopore sequencing, resulting in broad concordance with existing whole-genome and reduced-representation bisulfite sequencing, while highlighting superior overage of mobile elements. These analyses demonstrate the ability of Nanopore sequencing to resolve the sequence and epigenetic profile of canine genomes.
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Affiliation(s)
- Peter Z Schall
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
| | - Paige A Winkler
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Vilma Yuzbasiyan-Gurkan
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
- Department of Microbiology and Molecular Genetics, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Jeffrey M Kidd
- Department of Human Genetics, University of Michigan, Ann Arbor, MI 48109, USA
- Department of Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA
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3
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Occelli LM, Zobel L, Stoddard J, Wagner J, Pasmanter N, Querubin J, Renner LM, Reynaga R, Winkler PA, Sun K, Marinho LFLP, O'Riordan CR, Frederick A, Lauer A, Tsang SH, Hauswirth WW, McGill TJ, Neuringer M, Michalakis S, Petersen-Jones SM. Development of a translatable gene augmentation therapy for CNGB1-retinitis pigmentosa. Mol Ther 2023; 31:2028-2041. [PMID: 37056049 PMCID: PMC10362398 DOI: 10.1016/j.ymthe.2023.04.005] [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: 01/19/2023] [Revised: 03/07/2023] [Accepted: 04/10/2023] [Indexed: 04/15/2023] Open
Abstract
In this study, we investigate a gene augmentation therapy candidate for the treatment of retinitis pigmentosa (RP) due to cyclic nucleotide-gated channel beta 1 (CNGB1) mutations. We use an adeno-associated virus serotype 5 with transgene under control of a novel short human rhodopsin promoter. The promoter/capsid combination drives efficient expression of a reporter gene (AAV5-RHO-eGFP) exclusively in rod photoreceptors in primate, dog, and mouse following subretinal delivery. The therapeutic vector (AAV5-RHO-CNGB1) delivered to the subretinal space of CNGB1 mutant dogs restores rod-mediated retinal function (electroretinographic responses and vision) for at least 12 months post treatment. Immunohistochemistry shows human CNGB1 is expressed in rod photoreceptors in the treated regions as well as restoration of expression and trafficking of the endogenous alpha subunit of the rod CNG channel required for normal channel formation. The treatment reverses abnormal accumulation of the second messenger, cyclic guanosine monophosphate, which occurs in rod photoreceptors of CNGB1 mutant dogs, confirming formation of a functional CNG channel. In vivo imaging shows long-term preservation of retinal structure. In conclusion, this study establishes the long-term efficacy of subretinal delivery of AAV5-RHO-CNGB1 to rescue the disease phenotype in a canine model of CNGB1-RP, confirming its suitability for future clinical development.
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Affiliation(s)
- Laurence M Occelli
- College of Veterinary Medicine, Michigan State University, 736 Wilson Road, East Lansing, MI 48864, USA
| | - Lena Zobel
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany; Department of Ophthalmology, University Hospital, LMU Munich, 80336 Munich, Germany
| | - Jonathan Stoddard
- Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185(th) Avenue, Beaverton, OR 97005, USA
| | - Johanna Wagner
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Nathaniel Pasmanter
- College of Veterinary Medicine, Michigan State University, 736 Wilson Road, East Lansing, MI 48864, USA
| | - Janice Querubin
- College of Veterinary Medicine, Michigan State University, 736 Wilson Road, East Lansing, MI 48864, USA
| | - Lauren M Renner
- Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185(th) Avenue, Beaverton, OR 97005, USA
| | - Rene Reynaga
- Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185(th) Avenue, Beaverton, OR 97005, USA
| | - Paige A Winkler
- College of Veterinary Medicine, Michigan State University, 736 Wilson Road, East Lansing, MI 48864, USA
| | - Kelian Sun
- College of Veterinary Medicine, Michigan State University, 736 Wilson Road, East Lansing, MI 48864, USA
| | - Luis Felipe L P Marinho
- College of Veterinary Medicine, Michigan State University, 736 Wilson Road, East Lansing, MI 48864, USA
| | | | - Amy Frederick
- Genomic Medicine Unit, Sanofi, 225 Second Avenue, Waltham, MA 02451, USA
| | - Andreas Lauer
- Casey Eye Institute, Oregon Health & Science University, 515 Campus Drive, Portland, OR 97239, USA
| | - Stephen H Tsang
- Jonas Children's Vision Care, Departments of Ophthalmology, Pathology and Cell Biology, Institute of Human Nutrition, Columbia Stem Cell Initiative, Vagelos College of Physicians and Surgeons, New York, NY 10032, USA
| | - William W Hauswirth
- Department of Ophthalmology, College of Medicine, University of Florida, Box 100284 HSC, Gainesville, FL 32610, USA
| | - Trevor J McGill
- Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185(th) Avenue, Beaverton, OR 97005, USA; Casey Eye Institute, Oregon Health & Science University, 515 Campus Drive, Portland, OR 97239, USA
| | - Martha Neuringer
- Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185(th) Avenue, Beaverton, OR 97005, USA; Casey Eye Institute, Oregon Health & Science University, 515 Campus Drive, Portland, OR 97239, USA
| | - Stylianos Michalakis
- Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany; Department of Ophthalmology, University Hospital, LMU Munich, 80336 Munich, Germany.
| | - Simon M Petersen-Jones
- College of Veterinary Medicine, Michigan State University, 736 Wilson Road, East Lansing, MI 48864, USA.
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Gerhardt MJ, Petersen-Jones SM, Michalakis S. CNG channel-related retinitis pigmentosa. Vision Res 2023; 208:108232. [PMID: 37054604 PMCID: PMC10373105 DOI: 10.1016/j.visres.2023.108232] [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: 02/13/2023] [Revised: 03/27/2023] [Accepted: 03/27/2023] [Indexed: 04/15/2023]
Abstract
The genes CNGA1 and CNGB1 encode the alpha and beta subunits of the rod CNG channel, a ligand-gated cation channel whose activity is controlled by cyclic guanosine monophosphate (cGMP). Autosomal inherited mutations in either of the genes lead to a progressive rod-cone retinopathy known as retinitis pigmentosa (RP). The rod CNG channel is expressed in the plasma membrane of the outer segment and functions as a molecular switch that converts light-mediated changes in cGMP into a voltage and Ca2+ signal. Here, we will first review the molecular properties and physiological role of the rod CNG channel and then discuss the characteristics of CNG-related RP. Finally, we will summarize recent activities in the field of gene therapy aimed at developing therapies for CNG-related RP.
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Affiliation(s)
- Maximilian J Gerhardt
- Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstraße 8, 80336 München, Germany
| | - Simon M Petersen-Jones
- College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, United States
| | - Stylianos Michalakis
- Department of Ophthalmology, University Hospital, LMU Munich, Mathildenstraße 8, 80336 München, Germany.
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Biology, Pathobiology and Gene Therapy of CNG Channel-Related Retinopathies. Biomedicines 2023; 11:biomedicines11020269. [PMID: 36830806 PMCID: PMC9953513 DOI: 10.3390/biomedicines11020269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 01/16/2023] [Accepted: 01/17/2023] [Indexed: 01/21/2023] Open
Abstract
The visual process begins with the absorption of photons by photopigments of cone and rod photoreceptors in the retina. In this process, the signal is first amplified by a cyclic guanosine monophosphate (cGMP)-based signaling cascade and then converted into an electrical signal by cyclic nucleotide-gated (CNG) channels. CNG channels are purely ligand-gated channels whose activity can be controlled by cGMP, which induces a depolarizing Na+/Ca2+ current upon binding to the channel. Structurally, CNG channels belong to the superfamily of pore-loop cation channels and share structural similarities with hyperpolarization-activated cyclic nucleotide (HCN) and voltage-gated potassium (KCN) channels. Cone and rod photoreceptors express distinct CNG channels encoded by homologous genes. Mutations in the genes encoding the rod CNG channel (CNGA1 and CNGB1) result in retinitis-pigmentosa-type blindness. Mutations in the genes encoding the cone CNG channel (CNGA3 and CNGB3) lead to achromatopsia. Here, we review the molecular properties of CNG channels and describe their physiological and pathophysiological roles in the retina. Moreover, we summarize recent activities in the field of gene therapy aimed at developing the first gene therapies for CNG channelopathies.
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Preclinical Models of Retinitis Pigmentosa. Methods Mol Biol 2022; 2560:181-215. [PMID: 36481897 DOI: 10.1007/978-1-0716-2651-1_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Retinitis pigmentosa (RP) is the name for a group of phenotypically-related heritable retinal degenerative disorders. Many genes have been implicated as causing variants of RP, and while the clinical phenotypes are remarkably similar, they may differ in age of onset, progression, and severity. Common inheritance patterns for specific genes connected with the development of the disorder include autosomal dominant, autosomal recessive, and X-linked. Modeling the disease in animals and other preclinical systems offers a cost-conscious, ethical, and time-efficient method for studying the disease subtypes. The history of RP models is briefly examined, and both naturally occurring and transgenic preclinical models of RP in many different organisms are discussed. Syndromic forms of RP and models thereof are reviewed as well.
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Abstract
PURPOSE Mutations in the cyclic nucleotide-gated (CNG) channel beta subunit (CNGB1) are an important cause of recessive retinitis pigmentosa. We identified a large animal model with a truncating mutation of CNGB1. This study reports the persistence of small, desensitized rod ERG responses in this model. METHODS Dark-, light-adapted and chromatic ERGs were recorded in CNGB1 mutant dogs and age and breed matched controls. Comparisons were made with a dog model known to completely lack rod function; young dogs with a mutation in the rod phosphodiesterase 6 alpha subunit (PDE6A-/-). Immunohistochemistry (IHC) to label the rod CNG alpha (CNGA1) and CNGB1 subunits was performed. RESULTS The dark-adapted ERG of CNGB1 mutant dogs had a raised response threshold with lack of normal rod response and a remaining cone response. Increasing stimulus strength resulted in the appearance of a separate, slower positive waveform following the dark-adapted cone b-wave. With increasing stimulus strength this increased in amplitude and became faster to merge with the initial b-wave. Comparison of responses from PDE6A-/- (cone only dogs) with CNGB1 mutant dogs to red and blue flashes and between dark-adapted and light-adapted responses supported the hypothesis that the CNGB1 mutant dog had residual desensitized rod responses. CNGB1 mutant dogs had a small amount of CNGA1 detectable in the outer segments. CONCLUSIONS CNGB1 mutant dogs have a residual ERG response from desensitized rods. This may be due to low levels of CNGA1 in outer segments.
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Park SA, Rhodes J, Iwabe S, Ying GS, Pan W, Huang J, Komáromy AM. Quantitative and qualitative characterization of retinal dystrophies in canine models of inherited retinal diseases using spectral domain optical coherence tomography (SD-OCT). Exp Eye Res 2022; 220:109106. [PMID: 35588783 PMCID: PMC9789526 DOI: 10.1016/j.exer.2022.109106] [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: 02/04/2022] [Revised: 04/19/2022] [Accepted: 05/06/2022] [Indexed: 12/26/2022]
Abstract
The purpose of this study was to establish spectral domain optical coherence tomography (SD-OCT) assessment data in well-established canine models of inherited retinal dystrophies: PDE6B-rod-cone dysplasia 1 (RCD1: early onset retinitis pigmentosa), PRCD-progressive rod-cone degeneration (PRCD: late onset retinitis pigmentosa), CNGB3-achromatopsia, and RPE65-Leber congenital amaurosis (LCA). High resolution SD-OCT images of the retina were acquired from both eyes in 5 planes: temporal; superotemporal; superior; nasal; and inferior in adult dogs with: RCD1 (n = 4 dogs, median age: 1.5 yrs); PRCD (n = 2, 4.3 yrs); LCA (n = 3, 5.2 yrs); achromatopsia (n = 3, 4.2 yrs); and wild types (wt, n = 6, 5.5 yrs). Total, inner and outer retinal thicknesses and ellipsoid zone were analyzed. In selected animals, histomorphometric evaluations were performed. In dogs with RCD1, PRCD, and LCA, the thickness of the outer retina was, compared to wt, significantly decreased (p ≤ 0.02) in all OCT imaging planes, and in superotemporal and inferior imaging planes in dogs with achromatopsia. No significant thinning was observed in inner retina thickness in any disease model except in the inferior imaging plane in dogs with RCD1. Dogs with RCD1, PRCD, and LCA had significantly more areas with disrupted ellipsoid zone in the presumed area centralis than wt (p ≤ 0.001). OCT findings provide baseline information for research of retinal dystrophies using these canine models.
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Affiliation(s)
- Shin Ae Park
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA; Department of Clinical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN, USA.
| | - Jamie Rhodes
- Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Simone Iwabe
- Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Gui-Shuang Ying
- Department of Ophthalmology, School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Wei Pan
- Department of Ophthalmology, School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Jiayan Huang
- Department of Ophthalmology, School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - András M Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA; Department of Clinical Sciences & Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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The Natural History of CNGB1-Related Retinopathy: A Longitudinal Phenotypic Analysis. Int J Mol Sci 2022; 23:ijms23126785. [PMID: 35743231 PMCID: PMC9245601 DOI: 10.3390/ijms23126785] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 06/13/2022] [Accepted: 06/15/2022] [Indexed: 02/01/2023] Open
Abstract
Cyclic nucleotide-gated channel β 1 (CNGB1) encodes a subunit of the rod cyclic nucleotide-gated channel. Pathogenic variants in CNGB1 are responsible for 4% of autosomal recessive retinitis pigmentosa (RP). Several treatment strategies show promise for treating inherited retinal degenerations, however relevant metrics of progression and sensitive clinical trial endpoints are needed to assess therapeutic efficacy. This study reports the natural history of CNGB1-related RP with a longitudinal phenotypic analysis of 33 molecularly-confirmed patients with a mean follow-up period of 4.5 ± 3.9 years (range 0-17). The mean best corrected visual acuity (BCVA) of the right eye was 0.31 ± 0.43 logMAR at baseline and 0.47 ± 0.63 logMAR at the final visit over the study period. The ellipsoid zone (EZ) length was measurable in at least one eye of 23 patients and had a mean rate of constriction of 178 ± 161 µm per year (range 1.0-661 µm), with 57% of patients having a decrease in EZ length of greater than 250 µm in a simulated two-year trial period. Hyperautofluorescent outer ring (hyperAF) area was measurable in 17 patients, with 10 patients not displaying a ring phenotype. The results support previous findings of CNGB1-related RP being a slowly progressive disease with patients maintaining visual acuity. Prospective deep phenotyping studies assessing multimodal retinal imaging and functional measures are now required to determine clinical endpoints to be used in a trial.
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Marinho LFLP, Occelli LM, Bortolini M, Sun K, Winkler PA, Montiani-Ferreira F, Petersen-Jones SM. Development of retinal bullae in dogs with progressive retinal atrophy. Vet Ophthalmol 2021; 25:109-117. [PMID: 34708922 PMCID: PMC10074838 DOI: 10.1111/vop.12932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 08/04/2021] [Accepted: 08/23/2021] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To report the development of focal bullous retinal detachments (bullae) in dogs with different forms of progressive retinal atrophy (PRA). PROCEDURES Dogs with three distinct forms of PRA (PRA-affected Whippets, German Spitzes and CNGB1-mutant Papillon crosses) were examined by indirect ophthalmoscopy and spectral domain optical coherence tomography (SD-OCT). Retinal bullae were monitored over time. One CNGB1-mutant dog was treated with gene augmentation therapy. The canine BEST1 gene coding region and flanking intronic sequence was sequenced in at least one affected dog of each breed. RESULTS Multiple focal bullous retinal detachments (bullae) were identified in PRA-affected dogs of all three types. They developed in 4 of 5 PRA-affected Whippets, 3 of 8 PRA-affected Germans Spitzes and 15 of 20 CNGB1-mutant dogs. The bullae appeared prior to marked retinal degeneration and became less apparent as retinal degeneration progressed. Bullae were not seen in any heterozygous animals of any of the types of PRA. Screening of the coding region and flanking intronic regions of the canine BEST1 gene failed to reveal any associated pathogenic variants. Retinal gene augmentation therapy in one of the CNGB1-mutant dogs appeared to prevent formation of bullae. CONCLUSIONS Retinal bullae were identified in dogs with three distinct forms of progressive retinal atrophy. The lesions develop prior to retinal thinning. This clinical change should be monitored for in dogs with PRA.
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Affiliation(s)
- Luis Felipe L P Marinho
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Laurence M Occelli
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Mariza Bortolini
- Department of Veterinary Medicine, Federal University of Paraná, Curitiba, PR, Brazil
| | - Kelian Sun
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | - Paige A Winkler
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
| | | | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, USA
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Wagner JE, Zobel L, Gerhardt MJ, O'Riordan CR, Frederick A, Petersen-Jones SM, Biel M, Michalakis S. In vivo potency testing of subretinal rAAV5.hCNGB1 gene therapy in the Cngb1 knockout mouse model of retinitis pigmentosa. Hum Gene Ther 2021; 32:1158-1170. [PMID: 34376057 DOI: 10.1089/hum.2021.121] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Retinitis pigmentosa type 45 (RP45) is an autosomal-recessively inherited blinding disease caused by mutations in the cyclic nucleotide gated channel subunit beta 1 (CNGB1) gene. In this study, we developed and tested a novel gene supplementation therapy suitable for clinical translation. To this end, we designed a recombinant adeno-associated virus (rAAV) vector carrying a genome that features a novel human rhodopsin promoter (hRHO194) driving rod-specific expression of full-length human CNGB1 (rAAV5.hCNGB1). rAAV5.hCNGB1 was evaluated for efficacy in the Cngb1 knockout (Cngb1-/-) mouse model of RP45. In particular, increasing doses of rAAV5.hCNGB1 were delivered via single subretinal injection in 4-week-old Cngb1-/- mice and the treatment effect was assessed over a follow-up period of 9 months at the level of (i) retinal morphology, (ii) retinal function, (iii) vision-guided behavior, and (iv) transgene expression. We found that subretinal treatment with rAAV5.hCNGB1 resulted in efficient expression of the human CNGB1 protein in mouse rods and was able to normalize the expression of the endogenous mouse CNGA1 subunit, which together with CNGB1 forms the native heterotetrameric cGMP-gated cation channel in rod photoreceptors. The treatment led to a dose-dependent recovery of rod photoreceptor-driven function and preservation of retinal morphology in Cngb1-/- mice. In summary, these results demonstrate the efficacy of hCNGB1 gene supplementation therapy in the Cngb1-/- mouse model of RP45 and support the translation of this approach towards future clinical application.
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Affiliation(s)
- Johanna E Wagner
- Ludwig-Maximilians-Universität München, 9183, Department of Pharmacy - Center for Drug Research, Munich, Bayern, Germany;
| | - Lena Zobel
- Ludwig-Maximilians-Universität München, 9183, Department of Pharmacy - Center for Drug Research, Munich, Bayern, Germany.,Ludwig-Maximilians-Universität München, 9183, University Hospital - Department of Ophthalmology, Munich, Bayern, Germany;
| | - Maximilian Joachim Gerhardt
- Ludwig-Maximilians-Universität München, 9183, University Hospital - Department of Ophthalmology, Munich, Bayern, Germany;
| | - Catherine R O'Riordan
- Sanofi Genzyme, 2194, Gene Therapy, Rare Diseases, Framingham, Massachusetts, United States; Catherine.O'
| | - Amy Frederick
- Sanofi Genzyme, 2194, Gene Therapy, Rare Diseases, Framingham, Massachusetts, United States;
| | - Simon M Petersen-Jones
- Michigan State University, Veterinary Medical Center, East Lansing, Michigan, United States;
| | - Martin Biel
- Ludwig-Maximilians-Universität München, 9183, Department of Pharmacy - Center for Drug Research, Munich, Bayern, Germany;
| | - Stylianos Michalakis
- Ludwig-Maximilians-Universität München, 9183, Department of Pharmacy - Center for Drug Research, Munich, Bayern, Germany.,Ludwig-Maximilians-Universität München, 9183, University Hospital - Department of Ophthalmology, Munich, Bayern, Germany;
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Occelli LM, Marinho F, Singh RK, Binette F, Nasonkin IO, Petersen-Jones SM. Subretinal Transplantation of Human Embryonic Stem Cell-Derived Retinal Tissue in a Feline Large Animal Model. J Vis Exp 2021:10.3791/61683. [PMID: 34424232 PMCID: PMC10029721 DOI: 10.3791/61683] [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] [Indexed: 10/31/2022] Open
Abstract
Retinal degenerative (RD) conditions associated with photoreceptor loss such as age-related macular degeneration (AMD), retinitis pigmentosa (RP) and Leber Congenital Amaurosis (LCA) cause progressive and debilitating vision loss. There is an unmet need for therapies that can restore vision once photoreceptors have been lost. Transplantation of human pluripotent stem cell (hPSC)-derived retinal tissue (organoids) into the subretinal space of an eye with advanced RD brings retinal tissue sheets with thousands of healthy mutation-free photoreceptors and has a potential to treat most/all blinding diseases associated with photoreceptor degeneration with one approved protocol. Transplantation of fetal retinal tissue into the subretinal space of animal models and people with advanced RD has been developed successfully but cannot be used as a routine therapy due to ethical concerns and limited tissue supply. Large eye inherited retinal degeneration (IRD) animal models are valuable for developing vision restoration therapies utilizing advanced surgical approaches to transplant retinal cells/tissue into the subretinal space. The similarities in globe size, and photoreceptor distribution (e.g., presence of macula-like region area centralis) and availability of IRD models closely recapitulating human IRD would facilitate rapid translation of a promising therapy to the clinic. Presented here is a surgical technique of transplanting hPSC-derived retinal tissue into the subretinal space of a large animal model allowing assessment of this promising approach in animal models.
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Affiliation(s)
- Laurence M Occelli
- College of Veterinary Medicine, Department of Small Animal Clinical Sciences, Michigan State University
| | - Felipe Marinho
- College of Veterinary Medicine, Department of Small Animal Clinical Sciences, Michigan State University
| | | | | | | | - Simon M Petersen-Jones
- College of Veterinary Medicine, Department of Small Animal Clinical Sciences, Michigan State University;
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Nassisi M, Smirnov VM, Solis Hernandez C, Mohand‐Saïd S, Condroyer C, Antonio A, Kühlewein L, Kempf M, Kohl S, Wissinger B, Nasser F, Ragi SD, Wang N, Sparrow JR, Greenstein VC, Michalakis S, Mahroo OA, Ba‐Abbad R, Michaelides M, Webster AR, Degli Esposti S, Saffren B, Capasso J, Levin A, Hauswirth WW, Dhaenens C, Defoort‐Dhellemmes S, Tsang SH, Zrenner E, Sahel J, Petersen‐Jones SM, Zeitz C, Audo I. CNGB1-related rod-cone dystrophy: A mutation review and update. Hum Mutat 2021; 42:641-666. [PMID: 33847019 PMCID: PMC8218941 DOI: 10.1002/humu.24205] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 03/26/2021] [Accepted: 04/08/2021] [Indexed: 12/29/2022]
Abstract
Cyclic nucleotide-gated channel β1 (CNGB1) encodes the 240-kDa β subunit of the rod photoreceptor cyclic nucleotide-gated ion channel. Disease-causing sequence variants in CNGB1 lead to autosomal recessive rod-cone dystrophy/retinitis pigmentosa (RP). We herein present a comprehensive review and analysis of all previously reported CNGB1 sequence variants, and add 22 novel variants, thereby enlarging the spectrum to 84 variants in total, including 24 missense variants (two of which may also affect splicing), 21 nonsense, 19 splicing defects (7 at noncanonical positions), 10 small deletions, 1 small insertion, 1 small insertion-deletion, 7 small duplications, and 1 gross deletion. According to the American College of Medical Genetics and Genomics classification criteria, 59 variants were considered pathogenic or likely pathogenic and 25 were variants of uncertain significance. In addition, we provide further phenotypic data from 34 CNGB1-related RP cases, which, overall, are in line with previous findings suggesting that this form of RP has long-term retention of useful central vision despite the early onset of night blindness, which is valuable for patient counseling, but also has implications for it being considered a priority target for gene therapy trials.
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Affiliation(s)
- Marco Nassisi
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
- Centre Hospitalier National d'Ophtalmologie des Quinze‐Vingts, INSERM‐DGOS CIC1423ParisFrance
- Department of Clinical Sciences and Community HealthUniversity of MilanMilanItaly
- Ophthalmological Unit, Fondazione IRCCS Ca' GrandaOspedale Maggiore PoliclinicoMilanItaly
| | - Vasily M. Smirnov
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
- Exploration de la vision et Neuro‐Ophthalmologie, CHU de LilleLilleFrance
- Faculté de MédecineUniversité de LilleLilleFrance
| | - Cyntia Solis Hernandez
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
| | - Saddek Mohand‐Saïd
- Centre Hospitalier National d'Ophtalmologie des Quinze‐Vingts, INSERM‐DGOS CIC1423ParisFrance
| | - Christel Condroyer
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
| | - Aline Antonio
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
| | - Laura Kühlewein
- University Eye Hospital, Centre for OphthalmologyUniversity of TübingenTübingenGermany
- Institute for Ophthalmic Research, Centre for OphthalmologyUniversity of TübingenTübingenGermany
| | - Melanie Kempf
- University Eye Hospital, Centre for OphthalmologyUniversity of TübingenTübingenGermany
| | - Susanne Kohl
- Institute for Ophthalmic Research, Centre for OphthalmologyUniversity of TübingenTübingenGermany
| | - Bernd Wissinger
- Institute for Ophthalmic Research, Centre for OphthalmologyUniversity of TübingenTübingenGermany
| | - Fadi Nasser
- University Eye Hospital, Centre for OphthalmologyUniversity of TübingenTübingenGermany
| | - Sara D. Ragi
- Department of OphthalmologyColumbia University, New YorkNew YorkUSA
| | - Nan‐Kai Wang
- Department of OphthalmologyColumbia University, New YorkNew YorkUSA
- College of MedicineChang Gung UniversityTaoyuanTaiwan
- Department of Ophthalmology, Chang Gung Memorial HospitalLinkou Medical CenterTaoyuanTaiwan
| | - Janet R. Sparrow
- Department of OphthalmologyColumbia University, New YorkNew YorkUSA
| | | | | | - Omar A. Mahroo
- Moorfields Eye HospitalLondonUK
- UCL Institute of Ophthalmology, University College LondonLondonUK
| | - Rola Ba‐Abbad
- Moorfields Eye HospitalLondonUK
- UCL Institute of Ophthalmology, University College LondonLondonUK
| | - Michel Michaelides
- Moorfields Eye HospitalLondonUK
- UCL Institute of Ophthalmology, University College LondonLondonUK
| | - Andrew R. Webster
- Moorfields Eye HospitalLondonUK
- UCL Institute of Ophthalmology, University College LondonLondonUK
| | - Simona Degli Esposti
- Moorfields Eye HospitalLondonUK
- UCL Institute of Ophthalmology, University College LondonLondonUK
| | - Brooke Saffren
- Philadelphia College of Osteopathic MedicinePhiladelphiaPennsylvaniaUSA
| | | | - Alex Levin
- Pediatric Ophthalmology and Ocular Genetics, Flaum Eye Institute, Pediatric Genetics, Golisano Children's HospitalUniversity of RochesterRochesterNew YorkUSA
| | | | - Claire‐Marie Dhaenens
- Univ. Lille, Inserm, CHU Lille, U1172‐LilNCog‐Lille Neuroscience & CognitionLilleFrance
| | | | - Stephen H. Tsang
- Department of OphthalmologyColumbia University, New YorkNew YorkUSA
- Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma LaboratoryNew YorkNew YorkUSA
- Department of Pathology and Cell BiologyColumbia UniversityNew YorkNew YorkUSA
- Stem Cell Initiative (CSCI), Institute of Human Nutrition, Vagelos College of Physicians and SurgeonsNew YorkNew YorkUSA
| | - Eberhart Zrenner
- University Eye Hospital, Centre for OphthalmologyUniversity of TübingenTübingenGermany
| | - Jose‐Alain Sahel
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
- Department of OphthalmologyThe University of Pittsburgh School of MedicinePittsburghPennsylvaniaUSA
- Fondation Ophtalmologique Adolphe de RothschildParisFrance
| | - Simon M. Petersen‐Jones
- Department of Small Animal Clinical SciencesMichigan State UniversityEast LansingMichiganUSA
| | - Christina Zeitz
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
| | - Isabelle Audo
- Sorbonne Université, Institut National de la Santé et de la Recherche Médicale, Centre National de la Recherche ScientifiqueInstitut de la VisionParisFrance
- Centre Hospitalier National d'Ophtalmologie des Quinze‐Vingts, INSERM‐DGOS CIC1423ParisFrance
- University College London Institute of OphthalmologyLondonUK
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ERG assessment of altered retinal function in canine models of retinitis pigmentosa and monitoring of response to translatable gene augmentation therapy. Doc Ophthalmol 2021; 143:171-184. [PMID: 33818677 DOI: 10.1007/s10633-021-09832-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 03/16/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE To analyze ERG responses from two dog models of retinitis pigmentosa, one due to a PDE6A mutation and the other a CNGB1 mutation, both to assess the effect of these mutations on retinal function and the ability of gene augmentation therapy to restore normal function. METHODS Scotopic and photopic ERGs from young affected and normal control dogs and affected dogs following AAV-mediated gene augmentation therapy were analyzed. Parameters reflecting rod and cone function were collected by modeling the descending slope of the a-wave to measure receptor response and sensitivity. Rod-driven responses were further assessed by Naka-Rushton fitting of the first limb of the scotopic b-wave luminance-response plot. RESULTS PDE6A-/- dogs showed a dramatic decrease in rod-driven responses with very reduced rod maximal responses and sensitivity. There was a minor reduction in the amplitude of maximal cone responses. In contrast, CNGB1-/- dogs had some residual rod responses with reduced amplitude and sensitivity and normal cone responses. Following gene augmentation therapy, rod parameters were substantially improved in both models with restoration of sensitivity parameters log S and log K and a large increase in log Rmax in keeping with rescue of normal rod phototransduction in the treated retinal regions. CONCLUSIONS Modeling of rod and cone a-waves and the luminance-response function of the scotopic b-wave characterized the loss of rod photoreceptor function in two dog models of retinitis pigmentosa and showed the effectiveness of gene augmentation therapy in restoring normal functional parameters.
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Radojevic B, Jones K, Klein M, Mauro-Herrera M, Kingsley R, Birch DG, Bennett LD. Variable expressivity in patients with autosomal recessive retinitis pigmentosa associated with the gene CNGB1. Ophthalmic Genet 2020; 42:15-22. [PMID: 33465333 DOI: 10.1080/13816810.2020.1832532] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE In a cohort of eight families (11 patients) with autosomal recessive retinitis pigmentosa (arRP), we clinically characterized disease associated with mutations in CNGB1. METHODS Visual function was determined by measuring the patients' visual acuity, dark- and light-adapted perimetry, and by full-field electroretinography. Retinal structure was evaluated with spectral-domain optical coherence tomography, fundus imaging, and autofluorescence imaging. RESULTS Age of onset ranged from 4 to 49 years (mean [SD] 26 [17], median 27 years). The age at visit was 27-54 years, mean 37 (17). The range of visual acuity was logMAR -0.1 to 1.3 (Snellen 20/16 to 20/400) in the right eye and -0.1 to 0.9 (Snellen 20/16 to 20/160) in the left eye. Electrophysiological testing in five patients showed an absence of the rod response. Cone responses ranged from normal to severely reduced. The patients exhibited loss of rod vision more severe than cone vision. Funduscopic images showed widespread retinal degeneration with pigment clumping, optic disk pallor, arteriole attenuation, and a peri-foveal ring of hyper autofluorescence. Three families were tested for olfactory dysfunction and results indicated mild to complete anosmia in individuals with mutations in CNGB1. Genetic analysis revealed 6 novel variants, c.2127 C > G, p.Phe709Leu; c.1431 C > A, p.Cys477*; c.2034 G > A, p.Trp678*; c.2092 T > C, p.Cys698Arg; and c.583 + 2 T > C, c.2305-34 G > A and 3 variants that have been previously described, c.2957A>T, p.Asn986Ile; c.2544dup, p.Leu849Alafs*3; and c.2492 + 1 G > A. DISCUSSION This is the first report for six novel CNGB1 variants associated with arRP. Two families had olfactory dysfunction in patients with arRP and family members who were heterozygous for a CNGB1 mutation. Additionally, findings demonstrated variable penetrance and expressivity of disease in these patients.
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Affiliation(s)
- Bojana Radojevic
- Department of Ophthalmology, University of Oklahoma Health Sciences Center , Oklahoma City, OK, USA
| | - Kaylie Jones
- Rose-Silverthorne Retinal Degenerations Laboratory, Retina Foundation of the Southwest , Dallas, TX, USA
| | - Martin Klein
- Rose-Silverthorne Retinal Degenerations Laboratory, Retina Foundation of the Southwest , Dallas, TX, USA
| | - Margarita Mauro-Herrera
- Department of Ophthalmology, University of Oklahoma Health Sciences Center , Oklahoma City, OK, USA
| | - Ronald Kingsley
- Department of Ophthalmology, University of Oklahoma Health Sciences Center , Oklahoma City, OK, USA.,Department of Ophthalmology, Dean McGee Eye Institute , Oklahoma City, OK, USA
| | - David G Birch
- Rose-Silverthorne Retinal Degenerations Laboratory, Retina Foundation of the Southwest , Dallas, TX, USA.,Department of Ophthalmology, UT Southwestern Medical Center , Dallas, TX, USA
| | - Lea D Bennett
- Department of Ophthalmology, University of Oklahoma Health Sciences Center , Oklahoma City, OK, USA.,Department of Ophthalmology, UT Southwestern Medical Center , Dallas, TX, USA
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16
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Deletion in the Bardet-Biedl Syndrome Gene TTC8 Results in a Syndromic Retinal Degeneration in Dogs. Genes (Basel) 2020; 11:genes11091090. [PMID: 32962042 PMCID: PMC7565673 DOI: 10.3390/genes11091090] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/12/2020] [Accepted: 09/15/2020] [Indexed: 02/06/2023] Open
Abstract
In golden retriever dogs, a 1 bp deletion in the canine TTC8 gene has been shown to cause progressive retinal atrophy (PRA), the canine equivalent of retinitis pigmentosa. In humans, TTC8 is also implicated in Bardet–Biedl syndrome (BBS). To investigate if the affected dogs only exhibit a non-syndromic PRA or develop a syndromic ciliopathy similar to human BBS, we recruited 10 affected dogs to the study. The progression of PRA for two of the dogs was followed for 2 years, and a rigorous clinical characterization allowed a careful comparison with primary and secondary characteristics of human BBS. In addition to PRA, the dogs showed a spectrum of clinical and morphological signs similar to primary and secondary characteristics of human BBS patients, such as obesity, renal anomalies, sperm defects, and anosmia. We used Oxford Nanopore long-read cDNA sequencing to characterize retinal full-length TTC8 transcripts in affected and non-affected dogs, the results of which suggest that three isoforms are transcribed in the retina, and the 1 bp deletion is a loss-of-function mutation, resulting in a canine form of Bardet–Biedl syndrome with heterogeneous clinical signs.
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17
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Occelli LM, Pasmanter N, Ayoub EE, Petersen-Jones SM. Changes in retinal layer thickness with maturation in the dog: an in vivo spectral domain - optical coherence tomography imaging study. BMC Vet Res 2020; 16:225. [PMID: 32605619 PMCID: PMC7329457 DOI: 10.1186/s12917-020-02390-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Accepted: 05/25/2020] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Retinal diseases are common in dogs. Some hereditary retinal dystrophies in dogs are important not only because they lead to vision loss but also because they show strong similarities to the orthologous human conditions. Advances in in vivo non-invasive retinal imaging allow the capture of retinal cross-section images that parallel low power microscopic examination of histological sections. Spectral domain - optical coherence tomography (SD-OCT) allows the measurement of retinal layer thicknesses and gives the opportunity for repeat examination to investigate changes in thicknesses in health (such as changes with maturation and age) and disease (following the course of retinal degenerative conditions). The purpose of this study was to use SD-OCT to measure retinal layer thicknesses in the dog during retinal maturation and over the first year of life. SD-OCT was performed on normal beagle cross dogs from 4 weeks of age to 52 weeks of age. To assess changes in layer thickness with age, measurements were taken from fixed regions in each of the 4 quadrants and the area centralis (the region important for most detailed vision). Additionally, changes in retinal layer thickness along vertical and horizontal planes passing through the optic nerve head were assessed. RESULTS In the four quadrants an initial thinning of retinal layers occurred over the first 12 to 15 weeks of life after which there was little change in thickness. However, in the area centralis there was a thickening of the photoreceptor layer over this time period which was mostly due to a lengthening of the photoreceptor inner/outer segment layer. The retina thinned with greater distances from the optic nerve head in both vertical and horizontal planes with the dorsal retina being thicker than the ventral retina. Most of the change in thickness with distance from the optic nerve head was due to difference in thickness of the inner retinal layers. The outer retinal layers remained more constant in thickness, particularly in the horizontal plane and dorsal to the optic nerve head. CONCLUSIONS These measurements will provide normative data for future studies.
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Affiliation(s)
- Laurence M. Occelli
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI 48824 USA
| | - Nate Pasmanter
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI 48824 USA
| | - Elias E. Ayoub
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI 48824 USA
| | - Simon M. Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road, D-208, East Lansing, MI 48824 USA
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18
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Hou N, Jiang N, Ma Y, Zou Y, Piao X, Liu S, Chen Q. Low-Complexity Repetitive Epitopes of Plasmodium falciparum Are Decoys for Humoural Immune Responses. Front Immunol 2020; 11:610. [PMID: 32351503 PMCID: PMC7174639 DOI: 10.3389/fimmu.2020.00610] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 03/17/2020] [Indexed: 01/18/2023] Open
Abstract
Induction of humoural immunity is critical for clinical protection against malaria. More than 100 malaria vaccine candidates have been investigated at different developmental stages, but with limited protection. One of the roadblocks constrains the development of malaria vaccines is the poor immunogenicity of the antigens. The objective of this study was to map the linear B-cell epitopes of the Plasmodium falciparum erythrocyte invasion-associated antigens with a purpose of understanding humoural responses and protection. We conducted a large-scale screen using overlapping peptide microarrays of 37 proteins from the P. falciparum parasite, most of which are invasion-associated antigens which have been tested in clinical settings as vaccine candidates, with sera from individuals with various infection episodes. Analysis of the epitome of the antigens revealed that the most immunogenic epitopes were predominantly located in the low-complexity regions of the proteins containing repetitive and/or glutamate-rich motifs in different sequence contexts. However, in vitro assay showed the antibodies specific for these epitopes did not show invasion inhibitory effect. These discoveries indicated that the low-complexity regions of the parasite proteins might drive immune responses away from functional domains, which may be an instructive finding for the rational design of vaccine candidates.
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Affiliation(s)
- Nan Hou
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Ning Jiang
- Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China.,The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, China
| | - Yu Ma
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Yang Zou
- Beijing Key Laboratory for Research on Prevention and Treatment of Tropical Diseases, Beijing Tropical Medicine Research Institute, Beijing Friendship Hospital, Capital Medical University, Beijing, China
| | - Xianyu Piao
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Shuai Liu
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China
| | - Qijun Chen
- NHC Key Laboratory of Systems Biology of Pathogens, Institute of Pathogen Biology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, China.,Key Laboratory of Livestock Infectious Diseases in Northeast China, Ministry of Education, Key Laboratory of Zoonosis, College of Animal Science and Veterinary Medicine, Shenyang Agricultural University, Shenyang, China.,The Research Unit for Pathogenic Mechanisms of Zoonotic Parasites, Chinese Academy of Medical Sciences, Shenyang, China
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19
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Winkler PA, Occelli LM, Petersen-Jones SM. Large Animal Models of Inherited Retinal Degenerations: A Review. Cells 2020; 9:cells9040882. [PMID: 32260251 PMCID: PMC7226744 DOI: 10.3390/cells9040882] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 03/30/2020] [Accepted: 03/31/2020] [Indexed: 12/13/2022] Open
Abstract
Studies utilizing large animal models of inherited retinal degeneration (IRD) have proven important in not only the development of translational therapeutic approaches, but also in improving our understanding of disease mechanisms. The dog is the predominant species utilized because spontaneous IRD is common in the canine pet population. Cats are also a source of spontaneous IRDs. Other large animal models with spontaneous IRDs include sheep, horses and non-human primates (NHP). The pig has also proven valuable due to the ease in which transgenic animals can be generated and work is ongoing to produce engineered models of other large animal species including NHP. These large animal models offer important advantages over the widely used laboratory rodent models. The globe size and dimensions more closely parallel those of humans and, most importantly, they have a retinal region of high cone density and denser photoreceptor packing for high acuity vision. Laboratory rodents lack such a retinal region and, as macular disease is a critical cause for vision loss in humans, having a comparable retinal region in model species is particularly important. This review will discuss several large animal models which have been used to study disease mechanisms relevant for the equivalent human IRD.
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20
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Pasmanter N, Petersen-Jones SM. A review of electroretinography waveforms and models and their application in the dog. Vet Ophthalmol 2020; 23:418-435. [PMID: 32196872 DOI: 10.1111/vop.12759] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 02/20/2020] [Accepted: 02/24/2020] [Indexed: 02/04/2023]
Abstract
Electroretinography (ERG) is a commonly used technique to study retinal function in both clinical and research ophthalmology. ERG responses can be divided into component waveforms, analysis of which can provide insight into the health and function of different types and populations of retinal cells. In dogs, ERG has been used in the characterization of normal retinal function, as well as the diagnosis of retinal diseases and measuring effects of treatment. While many components of the recorded waveform are similar across species, dogs have several notable features that should be differentiated from the responses in humans and other animals. Additionally, modifications of standard protocols, such as changing flash frequency and stimulus color, and mathematical models of ERG waveforms have been used in studies of human retinal function but have been infrequently applied to visual electrophysiology in dogs. This review provides an overview of the origins and applications of ERG in addition to potential avenues for further characterization of responses in the dog.
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Affiliation(s)
- Nathaniel Pasmanter
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI, USA
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21
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Blond F, Léveillard T. Functional Genomics of the Retina to Elucidate its Construction and Deconstruction. Int J Mol Sci 2019; 20:E4922. [PMID: 31590277 PMCID: PMC6801968 DOI: 10.3390/ijms20194922] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 10/01/2019] [Indexed: 12/20/2022] Open
Abstract
The retina is the light sensitive part of the eye and nervous tissue that have been used extensively to characterize the function of the central nervous system. The retina has a central position both in fundamental biology and in the physiopathology of neurodegenerative diseases. We address the contribution of functional genomics to the understanding of retinal biology by reviewing key events in their historical perspective as an introduction to major findings that were obtained through the study of the retina using genomics, transcriptomics and proteomics. We illustrate our purpose by showing that most of the genes of interest for retinal development and those involved in inherited retinal degenerations have a restricted expression to the retina and most particularly to photoreceptors cells. We show that the exponential growth of data generated by functional genomics is a future challenge not only in terms of storage but also in terms of accessibility to the scientific community of retinal biologists in the future. Finally, we emphasize on novel perspectives that emerge from the development of redox-proteomics, the new frontier in retinal biology.
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Affiliation(s)
- Frédéric Blond
- Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
| | - Thierry Léveillard
- Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
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22
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Charbel Issa P, Reuter P, Kühlewein L, Birtel J, Gliem M, Tropitzsch A, Whitcroft KL, Bolz HJ, Ishihara K, MacLaren RE, Downes SM, Oishi A, Zrenner E, Kohl S, Hummel T. Olfactory Dysfunction in Patients With CNGB1-Associated Retinitis Pigmentosa. JAMA Ophthalmol 2019; 136:761-769. [PMID: 29800053 DOI: 10.1001/jamaophthalmol.2018.1621] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Importance Co-occurrence of retinitis pigmentosa (RP) and olfactory dysfunction may have a common genetic cause. Objective To report olfactory function and the retinal phenotype in patients with biallelic mutations in CNGB1, a gene coding for a signal transduction channel subunit expressed in rod photoreceptors and olfactory sensory neurons. Design, Setting, and Participants This case series was conducted from August 2015 through July 2017. The setting was a multicenter study involving 4 tertiary referral centers for inherited retinal dystrophies. Participants were 9 patients with CNGB1-associated RP. Main Outcomes and Measures Results of olfactory testing, ocular phenotyping, and molecular genetic testing using targeted next-generation sequencing. Results Nine patients were included in the study, 3 of whom were female. Their ages ranged between 34 and 79 years. All patients had an early onset of night blindness but were usually not diagnosed as having RP before the fourth decade because of slow retinal degeneration. Retinal features were characteristic of a rod-cone dystrophy. Olfactory testing revealed reduced or absent olfactory function, with all except one patient scoring in the lowest quartile in relation to age-related norms. Brain magnetic resonance imaging and electroencephalography measurements in response to olfactory stimulation were available for 1 patient and revealed no visible olfactory bulbs and reduced responses to odor, respectively. Molecular genetic testing identified 5 novel (c.1312C>T, c.2210G>A, c.2492+1G>A, c.2763C>G, and c.3044_3050delGGAAATC) and 5 previously reported mutations in CNGB1. Conclusions and Relevance Mutations in CNGB1 may cause an autosomal recessive RP-olfactory dysfunction syndrome characterized by a slow progression of retinal degeneration and variable anosmia or hyposmia.
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Affiliation(s)
- Peter Charbel Issa
- Oxford Eye Hospital, Oxford University Hospitals National Health Service (NHS) Foundation Trust, Oxford, United Kingdom.,Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.,Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Peggy Reuter
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Laura Kühlewein
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Johannes Birtel
- Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Martin Gliem
- Oxford Eye Hospital, Oxford University Hospitals National Health Service (NHS) Foundation Trust, Oxford, United Kingdom.,Department of Ophthalmology, University of Bonn, Bonn, Germany
| | - Anke Tropitzsch
- Department of Otorhinolaryngology-Head and Neck Surgery, University of Tübingen, Tübingen, Germany
| | - Katherine L Whitcroft
- University College London (UCL) Ear Institute and Royal National Throat, Nose and Ear Hospital, London, United Kingdom.,Centre for the Study of the Senses, Institute of Philosophy, School of Advanced Study, University of London, London, United Kingdom.,Smell and Taste Clinic, Department of Otorhinolaryngology-Head and Neck Surgery, Technische Universität Dresden, Dresden, Germany
| | - Hanno J Bolz
- Bioscientia Center for Human Genetics, Ingelheim, Germany.,Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
| | - Kenji Ishihara
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Robert E MacLaren
- Oxford Eye Hospital, Oxford University Hospitals National Health Service (NHS) Foundation Trust, Oxford, United Kingdom.,Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Susan M Downes
- Oxford Eye Hospital, Oxford University Hospitals National Health Service (NHS) Foundation Trust, Oxford, United Kingdom.,Nuffield Laboratory of Ophthalmology, Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Akio Oishi
- Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Eberhart Zrenner
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology-Head and Neck Surgery, Technische Universität Dresden, Dresden, Germany
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23
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Identification of a CNGB1 Frameshift Mutation in a Han Chinese Family with Retinitis Pigmentosa. Optom Vis Sci 2019; 95:1155-1161. [PMID: 30451805 DOI: 10.1097/opx.0000000000001305] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
SIGNIFICANCE Retinitis pigmentosa (RP) is a severe hereditary retinal disorder characterized by progressive degeneration of rod and cone photoreceptors. This study identified a novel frameshift mutation, c.385delC, p.(L129WfsTer148), in the cyclic nucleotide-gated channel beta 1 (CNGB1) gene of a consanguineous Han Chinese family with autosomal recessive RP (arRP). This expands the spectrum of CNGB1 gene variants in RP cases and possibly refines future genetic counseling. PURPOSE The present study sought to identify potential pathogenetic gene mutations in a five-generation consanguineous Han Chinese family with RP. METHODS Two members of a five-generation consanguineous Han Chinese pedigree with arRP and 100 normal individuals were enrolled in this study. Exome sequencing was performed on the 70-year-old male proband from a consanguineous family to screen potential pathogenic mutations according to the American College of Medical Genetics and Genomics for the interpretation of sequence variants. Sanger sequencing was performed on the proband, the proband's unaffected son, and 100 normal individuals to verify the disease-causing mutation. RESULTS A novel frameshift mutation, c.385delC, p.(L129WfsTer148), with homozygous status in the CNGB1 gene was identified in the proband of the family with arRP, and the mutation with heterozygous status was carried by the asymptomatic son. CONCLUSIONS The c.385delC (p.(L129WfsTer148)) mutation in the CNGB1 gene screened by exome sequencing is probably responsible for the RP phenotype in this family. The result expands the spectrum of CNGB1 gene variants in RP cases and possibly refines future genetic counseling.
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Complex Structural PPT1 Variant Associated with Non-syndromic Canine Retinal Degeneration. G3-GENES GENOMES GENETICS 2019; 9:425-437. [PMID: 30541930 PMCID: PMC6385984 DOI: 10.1534/g3.118.200859] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Rod and cone photoreceptors are specialized retinal neurons that have a fundamental role in visual perception, capturing light and transducing it into a neuronal signal. Aberrant functioning of rod and/or cone photoreceptors can ultimately lead to progressive degeneration and eventually blindness. In man, many rod and rod-cone degenerative diseases are classified as forms of retinitis pigmentosa (RP). Dogs also have a comparable disease grouping termed progressive retinal atrophy (PRA). These diseases are generally due to single gene defects and follow Mendelian inheritance.We collected 51 DNA samples from Miniature Schnauzers affected by PRA (average age of diagnosis ∼3.9 ±1 years), as well as from 56 clinically normal controls of the same breed (average age ∼6.6 ±2.8 years). Pedigree analysis suggested monogenic autosomal recessive inheritance of PRA. GWAS and homozygosity mapping defined a critical interval in the first 4,796,806 bp of CFA15. Whole genome sequencing of two affected cases, a carrier and a control identified two candidate variants within the critical interval. One was an intronic SNV in HIVEP3, and the other was a complex structural variant consisting of the duplication of exon 5 of the PPT1 gene along with a conversion and insertion (named PPT1dci). PPT1dci was confirmed homozygous in a cohort of 22 cases, and 12 more cases were homozygous for the CFA15 haplotype. Additionally, the variant was found homozygous in 6 non-affected dogs of age higher than the average age of onset. The HIVEP3 variant was found heterozygous (n = 4) and homozygous wild-type (n = 1) in cases either homozygous for PPT1dci or for the mapped CFA15 haplotype. We detected the wildtype and three aberrant PPT1 transcripts in isolated white blood cell mRNA extracted from a PRA case homozygous for PPT1dci, and the aberrant transcripts involved inclusion of the duplicated exon 5 and novel exons following the activation of cryptic splice sites. No neurological signs were detected among the dogs homozygous for the PPT1dci variant. Therefore, we propose PPT1dci as causative for a non-syndromic form of PRA (PRAPPT1) that shows incomplete penetrance in Miniature Schnauzers, potentially related to the presence of the wild-type transcript. To our knowledge, this is the first case of isolated retinal degeneration associated with a PPT1 variant.
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25
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Takahashi VKL, Takiuti JT, Jauregui R, Tsang SH. Gene therapy in inherited retinal degenerative diseases, a review. Ophthalmic Genet 2018; 39:560-568. [PMID: 30040511 DOI: 10.1080/13816810.2018.1495745] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Hereditary diseases of the retina represent a group of diseases with several heterogeneous mutations that have the common end result of progressive photoreceptor death leading to blindness. Retinal degenerations encompass multifactorial diseases such as age-related macular degeneration, Leber congenital amaurosis, Stargardt disease, and retinitis pigmentosa. Although there is currently no cure for degenerative retinal diseases, ophthalmology has been at the forefront of the development of gene therapy, which offers hope for the treatment of these conditions. This article will explore an overview of the clinical trials of gene supplementation therapy for retinal diseases that are underway or planned for the near future.
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Affiliation(s)
- Vitor K L Takahashi
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,c Department of Ophthalmology , Federal University of São Paulo , São Paulo , Brazil
| | - Júlia T Takiuti
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,d Division of Ophthalmology , University of São Paulo Medical School , São Paulo , Brazil
| | - Ruben Jauregui
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,e Weill Cornell Medical College , New York , NY , USA
| | - Stephen H Tsang
- a Department of Ophthalmology , Columbia University , New York , NY , USA.,b Departments of Ophthalmology, Pathology & Cell Biology,Columbia Stem Cell Initiative, Institute of Human Nutrition , Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Columbia University , New York , NY , USA.,f Department of Pathology & Cell Biology, Stem Cell Initiative (CSCI), Institute of Human Nutrition, College of Physicians and Surgeons , Columbia University , New York , NY , USA
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26
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Abstract
The first step in vision is the absorption of photons by the photopigments in cone and rod photoreceptors. After initial amplification within the phototransduction cascade the signal is translated into an electrical signal by the action of cyclic nucleotide-gated (CNG) channels. CNG channels are ligand-gated ion channels that are activated by the binding of cyclic guanosine monophosphate (cGMP) or cyclic adenosine monophosphate (cAMP). Retinal CNG channels transduce changes in intracellular concentrations of cGMP into changes of the membrane potential and the Ca2+ concentration. Structurally, the CNG channels belong to the superfamily of pore-loop cation channels and share a common gross structure with hyperpolarization-activated cyclic nucleotide-gated (HCN) channels and voltage-gated potassium channels (KCN). In this review, we provide an overview on the molecular properties of CNG channels and describe their physiological role in the phototransduction pathways. We also discuss insights into the pathophysiological role of CNG channel proteins that have emerged from the analysis of CNG channel-deficient animal models and human CNG channelopathies. Finally, we summarize recent gene therapy activities and provide an outlook for future clinical application.
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Affiliation(s)
- Stylianos Michalakis
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr, 5-13, 81377 Munich, Germany.
| | - Elvir Becirovic
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr, 5-13, 81377 Munich, Germany.
| | - Martin Biel
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy-Center for Drug Research, Ludwig-Maximilians-Universität München, Butenandtstr, 5-13, 81377 Munich, Germany.
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27
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Petersen-Jones SM, Occelli LM, Winkler PA, Lee W, Sparrow JR, Tsukikawa M, Boye SL, Chiodo V, Capasso JE, Becirovic E, Schön C, Seeliger MW, Levin AV, Michalakis S, Hauswirth WW, Tsang SH. Patients and animal models of CNGβ1-deficient retinitis pigmentosa support gene augmentation approach. J Clin Invest 2017; 128:190-206. [PMID: 29202463 PMCID: PMC5749539 DOI: 10.1172/jci95161] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 10/10/2017] [Indexed: 01/07/2023] Open
Abstract
Retinitis pigmentosa (RP) is a major cause of blindness that affects 1.5 million people worldwide. Mutations in cyclic nucleotide-gated channel β 1 (CNGB1) cause approximately 4% of autosomal recessive RP. Gene augmentation therapy shows promise for treating inherited retinal degenerations; however, relevant animal models and biomarkers of progression in patients with RP are needed to assess therapeutic outcomes. Here, we evaluated RP patients with CNGB1 mutations for potential biomarkers of progression and compared human phenotypes with those of mouse and dog models of the disease. Additionally, we used gene augmentation therapy in a CNGβ1-deficient dog model to evaluate potential translation to patients. CNGB1-deficient RP patients and mouse and dog models had a similar phenotype characterized by early loss of rod function and slow rod photoreceptor loss with a secondary decline in cone function. Advanced imaging showed promise for evaluating RP progression in human patients, and gene augmentation using adeno-associated virus vectors robustly sustained the rescue of rod function and preserved retinal structure in the dog model. Together, our results reveal an early loss of rod function in CNGB1-deficient patients and a wide window for therapeutic intervention. Moreover, the identification of potential biomarkers of outcome measures, availability of relevant animal models, and robust functional rescue from gene augmentation therapy support future work to move CNGB1-RP therapies toward clinical trials.
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Affiliation(s)
- Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, Michigan, USA
| | - Laurence M Occelli
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, Michigan, USA
| | - Paige A Winkler
- Department of Small Animal Clinical Sciences, Michigan State University, East Lansing, Michigan, USA
| | - Winston Lee
- Department of Ophthalmology Pathology & Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Janet R Sparrow
- Department of Ophthalmology Pathology & Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA
| | - Mai Tsukikawa
- Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Sanford L Boye
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Vince Chiodo
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Jenina E Capasso
- Ocular Genetics, Wills Eye Hospital (WEH), Philadelphia, Pennsylvania, USA
| | - Elvir Becirovic
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Christian Schön
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Mathias W Seeliger
- Division of Ocular Neurodegeneration, Institute for Ophthalmic Research, Centre for Ophthalmology, University of Tübingen, Tübingen, Germany
| | - Alex V Levin
- Thomas Jefferson University, Philadelphia, Pennsylvania, USA.,Ocular Genetics, Wills Eye Hospital (WEH), Philadelphia, Pennsylvania, USA
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich (CIPSM), Department of Pharmacy - Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - William W Hauswirth
- Department of Ophthalmology, University of Florida, Gainesville, Florida, USA
| | - Stephen H Tsang
- Department of Ophthalmology Pathology & Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, USA.,Edward S. Harkness Eye Institute, New York-Presbyterian Hospital, New York, New York, USA.,Jonas Children's Vision Care and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Ophthalmology, Columbia University Medical Center (CUMC), Edward S. Harkness Eye Institute, New York, New York, USA
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28
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Everson R, Pettitt L, Forman OP, Dower-Tylee O, McLaughlin B, Ahonen S, Kaukonen M, Komáromy AM, Lohi H, Mellersh CS, Sansom J, Ricketts SL. An intronic LINE-1 insertion in MERTK is strongly associated with retinopathy in Swedish Vallhund dogs. PLoS One 2017; 12:e0183021. [PMID: 28813472 PMCID: PMC5558984 DOI: 10.1371/journal.pone.0183021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 07/30/2017] [Indexed: 12/31/2022] Open
Abstract
The domestic dog segregates a significant number of inherited progressive retinal diseases, several of which mirror human retinal diseases and which are collectively termed progressive retinal atrophy (PRA). In 2014, a novel form of PRA was reported in the Swedish Vallhund breed, and the disease was mapped to canine chromosome 17. The causal mutation was not identified, but expression analyses of the retinas of affected Vallhunds demonstrated a 6-fold increased expression of the MERTK gene compared to unaffected dogs. Using 24 retinopathy cases and 97 controls with no clinical signs of retinopathy, we replicated the chromosome 17 association in Swedish Vallhunds from the UK and aimed to elucidate the causal variant underlying this association using whole genome sequencing (WGS) of an affected dog. This revealed a 6-8 kb insertion in intron 1 of MERTK that was not present in WGS of 49 dogs of other breeds. Sequencing and BLASTN analysis of the inserted segment was consistent with the insertion comprising a full-length intact LINE-1 retroelement. Testing of the LINE-1 insertion for association with retinopathy in the UK set of 24 cases and 97 controls revealed a strong statistical association (P-value 6.0 x 10-11) that was subsequently replicated in the original Finnish study set (49 cases and 89 controls (P-value 4.3 x 10-19). In a pooled analysis of both studies (73 cases and 186 controls), the LINE-1 insertion was associated with a ~20-fold increased risk of retinopathy (odds ratio 23.41, 95% confidence intervals 10.99-49.86, P-value 1.3 x 10-27). Our study adds further support for regulatory disruption of MERTK in Swedish Vallhund retinopathy; however, further work is required to establish a functional overexpression model. Future work to characterise the mechanism by which this intronic mutation disrupts gene regulation will further improve the understanding of MERTK biology and its role in retinal function.
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Affiliation(s)
- Richard Everson
- Centre for Small Animal Studies–Ophthalmology Unit, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Louise Pettitt
- Canine Genetics Research Group, Kennel Club Genetics Centre, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Oliver P. Forman
- Canine Genetics Research Group, Kennel Club Genetics Centre, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Olivia Dower-Tylee
- Canine Genetics Research Group, Kennel Club Genetics Centre, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Bryan McLaughlin
- Canine Genetics Research Group, Kennel Club Genetics Centre, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Saija Ahonen
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- The Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Maria Kaukonen
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- The Folkhälsan Institute of Genetics, Helsinki, Finland
| | - András M. Komáromy
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
- Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Hannes Lohi
- Department of Veterinary Biosciences and Research Programs Unit, Molecular Neurology, University of Helsinki, Helsinki, Finland
- The Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Cathryn S. Mellersh
- Canine Genetics Research Group, Kennel Club Genetics Centre, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Jane Sansom
- Centre for Small Animal Studies–Ophthalmology Unit, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
| | - Sally L. Ricketts
- Canine Genetics Research Group, Kennel Club Genetics Centre, Animal Health Trust, Kentford, Newmarket, Suffolk, United Kingdom
- * E-mail:
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29
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Yeh CY, Koehl KL, Harman CD, Iwabe S, Guzman JM, Petersen-Jones SM, Kardon RH, Komáromy AM. Assessment of Rod, Cone, and Intrinsically Photosensitive Retinal Ganglion Cell Contributions to the Canine Chromatic Pupillary Response. Invest Ophthalmol Vis Sci 2017; 58:65-78. [PMID: 28061512 PMCID: PMC5231906 DOI: 10.1167/iovs.16-19865] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Purpose The purpose of this study was to evaluate a chromatic pupillometry protocol for specific functional assessment of rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs) in dogs. Methods Chromatic pupillometry was tested and compared in 37 dogs in different stages of primary loss of rod, cone, and combined rod/cone and optic nerve function, and in 5 wild-type (WT) dogs. Eyes were stimulated with 1-s flashes of dim (1 cd/m2) and bright (400 cd/m2) blue light (for scotopic conditions) or bright red (400 cd/m2) light with 25-cd/m2 blue background (for photopic conditions). Canine retinal melanopsin/Opn4 was cloned, and its expression was evaluated using real-time quantitative reverse transcription-PCR and immunohistochemistry. Results Mean ± SD percentage of pupil constriction amplitudes induced by scotopic dim blue (scDB), scotopic bright blue (scBB), and photopic bright red (phBR) lights in WT dogs were 21.3% ± 10.6%, 50.0% ± 17.5%, and 19.4% ± 7.4%, respectively. Melanopsin-mediated responses to scBB persisted for several minutes (7.7 ± 4.6 min) after stimulus offset. In dogs with inherited retinal degeneration, loss of rod function resulted in absent scDB responses, followed by decreased phBR responses with disease progression and loss of cone function. Primary loss of cone function abolished phBR responses but preserved those responses to blue light (scDB and scBB). Although melanopsin/Opn4 expression was diminished with retinal degeneration, melanopsin-expressing ipRGCs were identified for the first time in both WT and degenerated canine retinas. Conclusions Pupil responses elicited by light stimuli of different colors and intensities allowed differential functional assessment of canine rods, cones, and ipRGCs. Chromatic pupillometry offers an effective tool for diagnosing retinal and optic nerve diseases.
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Affiliation(s)
- Connie Y Yeh
- College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States 2School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Kristin L Koehl
- College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States
| | - Christine D Harman
- College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States
| | - Simone Iwabe
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - José M Guzman
- School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Simon M Petersen-Jones
- College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States
| | - Randy H Kardon
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States 4Veterans Affairs Health Care System, Iowa City, Iowa, United States
| | - András M Komáromy
- College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States 2School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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30
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Broadgate S, Yu J, Downes SM, Halford S. Unravelling the genetics of inherited retinal dystrophies: Past, present and future. Prog Retin Eye Res 2017; 59:53-96. [PMID: 28363849 DOI: 10.1016/j.preteyeres.2017.03.003] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 03/21/2017] [Accepted: 03/23/2017] [Indexed: 02/07/2023]
Abstract
The identification of the genes underlying monogenic diseases has been of interest to clinicians and scientists for many years. Using inherited retinal dystrophies as an example of monogenic disease we describe the history of molecular genetic techniques that have been pivotal in the discovery of disease causing genes. The methods that were developed in the 1970's and 80's are still in use today but have been refined and improved. These techniques enabled the concept of the Human Genome Project to be envisaged and ultimately realised. When the successful conclusion of the project was announced in 2003 many new tools and, as importantly, many collaborations had been developed that facilitated a rapid identification of disease genes. In the post-human genome project era advances in computing power and the clever use of the properties of DNA replication has allowed the development of next-generation sequencing technologies. These methods have revolutionised the identification of disease genes because for the first time there is no need to define the position of the gene in the genome. The use of next generation sequencing in a diagnostic setting has allowed many more patients with an inherited retinal dystrophy to obtain a molecular diagnosis for their disease. The identification of novel genes that have a role in the development or maintenance of retinal function is opening up avenues of research which will lead to the development of new pharmacological and gene therapy approaches. Neither of which can be used unless the defective gene and protein is known. The continued development of sequencing technologies also holds great promise for the advent of truly personalised medicine.
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Affiliation(s)
- Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Jing Yu
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Susan M Downes
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, OX3 9DU, UK
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK.
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31
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Somma AT, Moreno JCD, Sato MT, Rodrigues BD, Bacellar-Galdino M, Occelli LM, Petersen-Jones SM, Montiani-Ferreira F. Characterization of a novel form of progressive retinal atrophy in Whippet dogs: a clinical, electroretinographic, and breeding study. Vet Ophthalmol 2016; 20:450-459. [PMID: 27896899 DOI: 10.1111/vop.12448] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE To describe a form of progressive retinal atrophy (PRA) in Whippets including clinical, electroretinographic, optical coherence tomographic changes and pedigree analysis. ANIMALS STUDIED Client-owned Whippet dogs (n = 51) living in Brazil. PROCEDURES All animals were submitted for routine ophthalmic screening for presumed inherited ocular disease, which included the following: visual tests, such as obstacle course tests, in scotopic and photopic conditions, cotton ball test, dazzle reflex, ocular fundus evaluation by indirect ophthalmoscopy followed by fundus photography. Additionally, electroretinography (ERG) and optical coherence tomography (OCT) were performed in 24 and four dogs, respectively. RESULTS Sixteen dogs were diagnosed with PRA. Vision deficits in dim light were detected in dogs examined at a young age associated with nystagmus. Funduscopic changes included the development of multifocal retinal bullae from 6 months of age. Retinal thinning became apparent later, at which time the bullae were no longer detected. OCT examination of selected young dogs revealed that the retinal bullae were due to separation between photoreceptors and the retinal pigment epithelium, and of dogs with more advanced disease confirmed the development of retinal thinning. Electroretinography in young dogs revealed a negative ERG due to a lack of b-wave in both scotopic and photopic recordings. With progression, the ERG became unrecordable. Pedigree analysis suggested an autosomal recessive mode of inheritance. CONCLUSION The retinal dystrophy reported here in Whippet dogs has a unique phenotype of an initial lack of ERG b-wave, development of retinal bullae then a progressive generalized retinal degeneration.
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Affiliation(s)
- André Tavares Somma
- Veterinary Medicine Department, Comparative Ophthalmology Laboratory, Rua dos Funcionários, 1540, Curtiba, 80035-050, Brazil
| | - Juan Carlos Duque Moreno
- Veterinary Medicine Department, Comparative Ophthalmology Laboratory, Rua dos Funcionários, 1540, Curtiba, 80035-050, Brazil
| | - Mario Teruo Sato
- Universidade Federal do Parana, R. Padre Camargo, 280, Curtiba, 80060-240, Brazil
| | - Blanche Dreher Rodrigues
- Ophthalmology Service, Centro Integrado de Especialidades Veterinárias, Rua André Zanetti, 144, Curtiba, 808010-280, Brazil
| | - Marianna Bacellar-Galdino
- Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road D-208, East Lansing, MI, 48824, USA
| | - Laurence Mireille Occelli
- Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road D-208, East Lansing, MI, 48824, USA
| | - Simon Michael Petersen-Jones
- Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road D-208, East Lansing, MI, 48824, USA
| | - Fabiano Montiani-Ferreira
- Veterinary Medicine Department, Comparative Ophthalmology Laboratory, Rua dos Funcionários, 1540, Curtiba, 80035-050, Brazil
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32
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Winkler PA, Davis JA, Petersen-Jones SM, Venta PJ, Bartoe JT. A tool set to allow rapid screening of dog families with PRA for association with candidate genes. Vet Ophthalmol 2016; 20:372-376. [DOI: 10.1111/vop.12401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Paige A. Winkler
- Department of Small Animal Clinical Sciences; College of Veterinary Medicine; Michigan State University; East Lansing MI 48824 USA
- Genetics Program; Michigan State University; East Lansing MI 48824 USA
| | - Jennifer A. Davis
- Psychiatry and Behavioral Neurobiology; University of Alabama at Birmingham; Birmingham AL 35294 USA
| | - Simon M. Petersen-Jones
- Department of Small Animal Clinical Sciences; College of Veterinary Medicine; Michigan State University; East Lansing MI 48824 USA
- Genetics Program; Michigan State University; East Lansing MI 48824 USA
| | - Patrick J. Venta
- Department of Small Animal Clinical Sciences; College of Veterinary Medicine; Michigan State University; East Lansing MI 48824 USA
- Genetics Program; Michigan State University; East Lansing MI 48824 USA
- Microbiology & Molecular Genetics; Michigan State University; East Lansing MI 48824 USA
| | - Joshua T. Bartoe
- Department of Small Animal Clinical Sciences; College of Veterinary Medicine; Michigan State University; East Lansing MI 48824 USA
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33
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Palanova A. The genetics of inherited retinal disorders in dogs: implications for diagnosis and management. VETERINARY MEDICINE-RESEARCH AND REPORTS 2016; 7:41-51. [PMID: 30050836 PMCID: PMC6042528 DOI: 10.2147/vmrr.s63537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
Dogs are affected by many hereditary diseases just as humans are. One group of these diseases comprises of retinal disorders, which are a growing problem in canine breeding. These disorders are heterogeneous, with diverse causative mutations and modes of inheritance. Some affect only one breed, while others may affect many breeds; some breeds are affected by only one disease, while others can be affected by two or more. Dog breeders should take into account the presence of any deleterious alleles when choosing parents for the next generation.
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Affiliation(s)
- Anna Palanova
- Department of Tumor Biology, Institute of Animal Physiology and Genetics, v. v. i., Academy of Sciences of the Czech Republic, Libechov, Czech Republic,
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Kumar P, Kumar D, Jha SK, Jha NK, Ambasta RK. Ion Channels in Neurological Disorders. ION CHANNELS AS THERAPEUTIC TARGETS, PART A 2016; 103:97-136. [DOI: 10.1016/bs.apcsb.2015.10.006] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Nemet I, Tian G, Imanishi Y. Organization of cGMP sensing structures on the rod photoreceptor outer segment plasma membrane. Channels (Austin) 2015; 8:528-35. [PMID: 25616687 DOI: 10.4161/19336950.2014.973776] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
A diffusion barrier segregates the plasma membrane of the rod photoreceptor outer segment into 2 domains; one which is optimized for the conductance of ions in the phototransduction cascade and another for disk membrane synthesis. We propose the former to be named "phototransductive plasma membrane domain," and the latter to be named "disk morphogenic plasma membrane domain." Within the phototransductive plasma membrane, cGMP-gated channels are concentrated in striated membrane features, which are proximally located to the sites of active cGMP production within the disk membranes. For proper localization of cGMP-gated channel to the phototransductive plasma membrane, the glutamic acid-rich protein domain encoded in the β subunit plays a critical role. Quantitative study suggests that the disk morphogenic domain likely plays an important role in enriching rhodopsin prior to its sequestration into closed disk membranes. Thus, this and our previous studies provide new insight into the mechanism that spatially organizes the vertebrate phototransduction cascade.
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Key Words
- CNGA1
- CNGA1, cyclic nucleotide gated channel α-1
- CNGB1
- CNGB1, cyclic nucleotide gated channel β-1
- Dend2, Dendra2
- GARP, glutamic acid-rich protein
- GC, guanylate cyclase
- GCAP, guanylate cyclase activating protein
- GPCR, G protein-coupled receptor
- IS, inner segment
- OS, outer segment
- PDE6, phosphodiesterase 6
- Rho, rhodopsin
- cyclic nucleotide gated channel
- morphogenesis
- photoreceptor
- retina
- rhodopsin
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Affiliation(s)
- Ina Nemet
- a Department of Pharmacology; School of Medicine ; Case Western Reserve University ; Cleveland , OH USA
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Wiik AC, Ropstad EO, Ekesten B, Karlstam L, Wade CM, Lingaas F. Progressive retinal atrophy in Shetland sheepdog is associated with a mutation in the CNGA1 gene. Anim Genet 2015. [PMID: 26202106 DOI: 10.1111/age.12323] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Progressive retinal atrophy (PRA) is the collective name of a class of hereditary retinal dystrophies in the dog and is often described as the equivalent of retinitis pigmentosa in humans. PRA is characterized by visual impairment due to degeneration of the photoreceptors in the retina, usually leading to blindness. PRA has been reported in dogs from more than 100 breeds and can be genetically heterogeneous both between and within breeds. The disease can be subdivided by age at onset and rate of progression. Using genome-wide association with 15 Shetland Sheepdog (Sheltie) cases and 14 controls, we identified a novel PRA locus on CFA13 (Praw = 8.55 × 10(-7) , Pgenome = 1.7 × 10(-4) ). CNGA1, which is known to be involved in human cases of retinitis pigmentosa, was located within the associated region and was considered a likely candidate gene. Sequencing of this gene identified a 4-bp deletion in exon 9 (c.1752_1755delAACT), leading to a frameshift and a premature stop codon. The study indicated genetic heterogeneity as the mutation was present in all PRA-affected individuals in one large family of Shelties, whereas some other cases in the studied Sheltie population were not associated with this CNGA1 mutation. To our knowledge, this is the first report of a mutation in CNGA1 causing PRA in dogs.
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Affiliation(s)
- A C Wiik
- Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences, NMBU, Postboks 8146 Dep, 0033, Oslo, Norway
| | - E O Ropstad
- Department of Companion Animal Clinical Sciences, Norwegian University of Life Sciences, NMBU, Postboks 8146 Dep, 0033, Oslo, Norway
| | - B Ekesten
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, Box 7054, 75007, Uppsala, Sweden
| | - L Karlstam
- Aros Veterinär Centrum, Olof Palmes Torg 10, 723 34, Västerås, Sweden
| | - C M Wade
- Faculty of Veterinary Science, The University of Sydney, Sydney, NSW, 2006, Australia
| | - F Lingaas
- Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences, NMBU, Postboks 8146 Dep, 0033, Oslo, Norway
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Svensson M, Olsén L, Winkler PA, Petersen-Jones SM, Bergström T, Garncarz Y, Narfström K. Progressive retinal atrophy in the Polski Owczarek Nizinny dog: a clinical and genetic study. Vet Ophthalmol 2015; 19:195-205. [PMID: 26009980 DOI: 10.1111/vop.12284] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To describe ophthalmic, functional, structural, and genetical characteristics of progressive retinal atrophy (PRA) in the polski owczarek nizinny (PON) breed of dog. ANIMALS STUDIED CLINICALLY Client-owned PON dogs (n = 82) from Sweden. PROCEDURES Routine examination for presumed inherited eye disease was performed in all dogs. Bilateral full-field electroretinography (ERG) was performed in 11 affected and 4 control dogs. Eyes from one affected dog were studied with light microscopy. DNA samples from 34 Swedish and 30 PON dogs collected by Michigan State University (MSU) were tested for the mutations causing the rcd4 and prcd forms of PRA. RESULTS Sixteen of the eighty-two Swedish dogs were diagnosed with PRA. Slight vascular attenuation, first seen at 4.5 years of age, preceded changes in tapetal reflectivity. The initial ERG changes in affected dogs showed markedly diminished rod responses, while cone responses were barely affected. Eventually, cone responses were also reduced. Retinal morphology showed approximately a 50% reduction of photoreceptor nuclei in the outer nuclear layer. Fourteen of fifteen PRA-affected Swedish dogs and eighteen of twenty of the MSU PRA-affected dogs tested genetically were positive for the rcd4 mutation. All tested dogs were negative for the mutation causing prcd-PRA. CONCLUSIONS PRA of PON dogs is a late-onset degenerative disease with slow progression. There is early loss of rod function, while the cone system deteriorates later. The rcd4 mutation in the C2ORF71 gene was associated with the majority of the PRA cases tested. The possibility of additional forms of PRA in the breed cannot be excluded.
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Affiliation(s)
- Marika Svensson
- Blue Star Animal Hospital, Gjutjärnsgatan 4, Gothenburg, 417 07, Sweden
| | - Lena Olsén
- Division of Pharmacology and Toxicology, Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Uppsala, SE-750 07, Sweden
| | - Paige A Winkler
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road D, 208, East Lansing, MI, USA.,Genetics Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Simon M Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, 736 Wilson Road D, 208, East Lansing, MI, USA.,Genetics Program, Michigan State University, East Lansing, MI, 48824, USA
| | - Tomas Bergström
- Department of Animal Breeding and Genetics, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Yacek Garncarz
- Veterinary Eye Clinic, Grupy AK Polnoc 2/u10, Warsaw, 00-713, Poland
| | - Kristina Narfström
- College of Veterinary Medicine, 900 East Campus Drive, Columbia, MO, 65211, USA.,Retvet KB, Karlsuddsvägen 14b, Vaxholm, 185 93, Sweden
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Petersen-Jones SM, Komáromy AM. Dog models for blinding inherited retinal dystrophies. HUM GENE THER CL DEV 2015; 26:15-26. [PMID: 25671556 DOI: 10.1089/humc.2014.155] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Spontaneous canine models exist for several inherited retinal dystrophies. This review will summarize the models and indicate where they have been used in translational gene therapy trials. The RPE65 gene therapy trials to treat childhood blindness are a good example of how studies in dogs have contributed to therapy development. Outcomes in human clinical trials are compared and contrasted with the result of the preclinical dog trials.
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Affiliation(s)
- Simon M Petersen-Jones
- 1 Department of Small Animal Clinical Sciences, Michigan State University , East Lansing, MI 48824
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Petersen-Jones S, Komaromy AM. Dog Models for Blinding Inherited Retinal Degenerations. HUM GENE THER CL DEV 2014. [DOI: 10.1089/hum.2014.155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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Mellersh CS. The genetics of eye disorders in the dog. Canine Genet Epidemiol 2014; 1:3. [PMID: 26401320 PMCID: PMC4574392 DOI: 10.1186/2052-6687-1-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 03/06/2014] [Indexed: 11/10/2022] Open
Abstract
Inherited forms of eye disease are arguably the best described and best characterized of all inherited diseases in the dog, at both the clinical and molecular level and at the time of writing 29 different mutations have been documented in the scientific literature that are associated with an inherited ocular disorder in the dog. The dog has already played an important role in the identification of genes that are important for ocular development and function as well as emerging therapies for inherited blindness in humans. Similarities in disease phenotype and eye structure and function between dog and man, together with the increasingly sophisticated genetic tools that are available for the dog, mean that the dog is likely to play an ever increasing role in both our understanding of the normal functioning of the eye and in our ability to treat inherited eye disorders. This review summarises the mutations that have been associated with inherited eye disorders in the dog.
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Winkler PA, Gornik KR, Ramsey DT, Dubielzig RR, Venta PJ, Petersen-Jones SM, Bartoe JT. A partial gene deletion of SLC45A2 causes oculocutaneous albinism in Doberman pinscher dogs. PLoS One 2014; 9:e92127. [PMID: 24647637 PMCID: PMC3960214 DOI: 10.1371/journal.pone.0092127] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Accepted: 02/17/2014] [Indexed: 02/04/2023] Open
Abstract
The first white Doberman pinscher (WDP) dog was registered by the American Kennel Club in 1976. The novelty of the white coat color resulted in extensive line breeding of this dog and her offspring. The WDP phenotype closely resembles human oculocutaneous albinism (OCA) and clinicians noticed a seemingly high prevalence of pigmented masses on these dogs. This study had three specific aims: (1) produce a detailed description of the ocular phenotype of WDPs, (2) objectively determine if an increased prevalence of ocular and cutaneous melanocytic tumors was present in WDPs, and (3) determine if a genetic mutation in any of the genes known to cause human OCA is causal for the WDP phenotype. WDPs have a consistent ocular phenotype of photophobia, hypopigmented adnexal structures, blue irides with a tan periphery and hypopigmented retinal pigment epithelium and choroid. WDPs have a higher prevalence of cutaneous melanocytic neoplasms compared with control standard color Doberman pinschers (SDPs); cutaneous tumors were noted in 12/20 WDP (<5 years of age: 4/12; >5 years of age: 8/8) and 1/20 SDPs (p<0.00001). Using exclusion analysis, four OCA causative genes were investigated for their association with WDP phenotype; TYR, OCA2, TYRP1 and SLC45A2. SLC45A2 was found to be linked to the phenotype and gene sequencing revealed a 4,081 base pair deletion resulting in loss of the terminus of exon seven of SLC45A2 (chr4∶77,062,968–77,067,051). This mutation is highly likely to be the cause of the WDP phenotype and is supported by a lack of detectable SLC45A2 transcript levels by reverse transcriptase PCR. The WDP provides a valuable model for studying OCA4 visual disturbances and melanocytic neoplasms in a large animal model.
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Affiliation(s)
- Paige A. Winkler
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
- Genetics Program, Michigan State University, East Lansing, Michigan, United States of America
| | - Kara R. Gornik
- Cummings School of Veterinary Medicine, Tufts University, North Grafton, Massachusetts, United States of America
| | - David T. Ramsey
- The Animal Ophthalmology Center, Williamston, Michigan, United States of America
| | - Richard R. Dubielzig
- Comparative Ocular Pathology Laboratory of Wisconsin, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Patrick J. Venta
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
- Genetics Program, Michigan State University, East Lansing, Michigan, United States of America
| | - Simon M. Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
- Genetics Program, Michigan State University, East Lansing, Michigan, United States of America
| | - Joshua T. Bartoe
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, Michigan, United States of America
- * E-mail:
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Miyadera K. Inherited retinal diseases in dogs: advances in gene/mutation discovery. DOBUTSU IDEN IKUSHU KENKYU = JOURNAL OF ANIMAL GENETICS 2014; 42:79-89. [PMID: 26120276 PMCID: PMC4480793 DOI: 10.5924/abgri.42.79] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
1. Inherited retinal diseases (RDs) are vision-threatening conditions affecting humans as well as many domestic animals. Through many years of clinical studies of the domestic dog population, a wide array of RDs has been phenotypically characterized. Extensive effort to map the causative gene and to identify the underlying mutation followed. Through candidate gene, linkage analysis, genome-wide association studies, and more recently, by means of next-generation sequencing, as many as 31 mutations in 24 genes have been identified as the underlying cause for canine RDs. Most of these genes have been associated with human RDs providing opportunities to study their roles in the disease pathogenesis and in normal visual function. The canine model has also contributed in developing new treatments such as gene therapy which has been clinically applied to human patients. Meanwhile, with increasing knowledge of the molecular architecture of RDs in different subpopulations of dogs, the conventional understanding of RDs as a simple monogenic disease is beginning to change. Emerging evidence of modifiers that alters the disease outcome is complicating the interpretation of DNA tests. In this review, advances in the gene/mutation discovery approaches and the emerging genetic complexity of canine RDs are discussed.
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Affiliation(s)
- Keiko Miyadera
- School of Veterinary Medicine, University of Pennsylvania, 3900 Delancey St, Philadelphia PA 19104 USA
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Petersen-Jones SM. Drug and gene therapy of hereditary retinal disease in dog and cat models. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.ddmod.2014.01.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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