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Scalabrino ML, Thapa M, Wang T, Sampath AP, Chen J, Field GD. Late gene therapy limits the restoration of retinal function in a mouse model of retinitis pigmentosa. Nat Commun 2023; 14:8256. [PMID: 38086857 PMCID: PMC10716155 DOI: 10.1038/s41467-023-44063-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 11/29/2023] [Indexed: 12/18/2023] Open
Abstract
Retinitis pigmentosa is an inherited photoreceptor degeneration that begins with rod loss followed by cone loss. This cell loss greatly diminishes vision, with most patients becoming legally blind. Gene therapies are being developed, but it is unknown how retinal function depends on the time of intervention. To uncover this dependence, we utilize a mouse model of retinitis pigmentosa capable of artificial genetic rescue. This model enables a benchmark of best-case gene therapy by removing variables that complicate answering this question. Complete genetic rescue was performed at 25%, 50%, and 70% rod loss (early, mid and late, respectively). Early and mid treatment restore retinal output to near wild-type levels. Late treatment retinas exhibit continued, albeit slowed, loss of sensitivity and signal fidelity among retinal ganglion cells, as well as persistent gliosis. We conclude that gene replacement therapies delivered after 50% rod loss are unlikely to restore visual function to normal. This is critical information for administering gene therapies to rescue vision.
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Affiliation(s)
- Miranda L Scalabrino
- Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles, CA, USA
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
| | - Mishek Thapa
- Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles, CA, USA
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA
| | - Tian Wang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Alapakkam P Sampath
- Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles, CA, USA
| | - Jeannie Chen
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Greg D Field
- Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles, CA, USA.
- Department of Neurobiology, Duke University School of Medicine, Durham, NC, USA.
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2
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Lozano B LL, Cervantes A LA. Development of experimental treatments for patients with retinitis pigmentosa. ARCHIVOS DE LA SOCIEDAD ESPANOLA DE OFTALMOLOGIA 2023; 98:646-655. [PMID: 37640142 DOI: 10.1016/j.oftale.2023.08.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 08/11/2023] [Indexed: 08/31/2023]
Abstract
Retinitis pigmentosa (RP) is a group of inherited diseases that lead to degeneration of the retina and decreased vision. The World Health Organization reports around 1,300 million people affected by some type of visual impairment worldwide. The prevalence is 1 in every 4000 inhabitants and it is the first cause of blindness of genetic origin, frequent in men with a percentage of 60% and 40% in women. There is a lack of information on this pathology in the world, mainly on the existing treatments for this disease, so this bibliographic review aims to update the existing or under-study treatments and inform the limitations of each of these therapies. This review of scientific literature was carried out by consulting databases such as PubMed and Web of science, the search will be limited to articles from the years 2018-2022. There are several types of therapy in studies: gene therapy, transcorneal electrical stimulation, use of neuroprotectors, optogenic therapy, stem cell transplants and oligonucleotide therapy, which will be discussed in this article, both their benefits and the existing barriers in each treatment experimental. In conclusion, each of these therapies promises a viable treatment in the future for selective groups of people with retinitis pigmentosa, however, some therapies have shown benefit at the beginning of the disease, losing their efficacy in the long term.
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Affiliation(s)
- L L Lozano B
- Universidad Católica de Cuenca, Cuenca, Ecuador.
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Friebe A, Kraehling JR, Russwurm M, Sandner P, Schmidtko A. The 10th International Conference on cGMP 2022: recent trends in cGMP research and development-meeting report. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:1669-1686. [PMID: 37079081 PMCID: PMC10338386 DOI: 10.1007/s00210-023-02484-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 03/31/2023] [Indexed: 04/21/2023]
Abstract
Increasing cGMP is a unique therapeutic principle, and drugs inhibiting cGMP-degrading enzymes or stimulating cGMP production are approved for the treatment of various diseases such as erectile dysfunction, coronary artery disease, pulmonary hypertension, chronic heart failure, irritable bowel syndrome, or achondroplasia. In addition, cGMP-increasing therapies are preclinically profiled or in clinical development for quite a broad set of additional indications, e.g., neurodegenerative diseases or different forms of dementias, bone formation disorders, underlining the pivotal role of cGMP signaling pathways. The fundamental understanding of the signaling mediated by nitric oxide-sensitive (soluble) guanylyl cyclase and membrane-associated receptor (particulate) guanylyl cyclase at the molecular and cellular levels, as well as in vivo, especially in disease models, is a key prerequisite to fully exploit treatment opportunities and potential risks that could be associated with an excessive increase in cGMP. Furthermore, human genetic data and the clinical effects of cGMP-increasing drugs allow back-translation into basic research to further learn about signaling and treatment opportunities. The biannual international cGMP conference, launched nearly 20 years ago, brings all these aspects together as an established and important forum for all topics from basic science to clinical research and pivotal clinical trials. This review summarizes the contributions to the "10th cGMP Conference on cGMP Generators, Effectors and Therapeutic Implications," which was held in Augsburg in 2022 but will also provide an overview of recent key achievements and activities in the field of cGMP research.
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Affiliation(s)
- Andreas Friebe
- Institute of Physiology, University of Würzburg, Röntgenring 9, D-97070 Würzburg, Germany
| | - Jan R. Kraehling
- Pharmaceuticals, Research and Early Development, Pharma Research Center, Bayer AG, Aprather Weg 18a, D-42096 Wuppertal, Germany
| | - Michael Russwurm
- Institute of Pharmacology, Ruhr-University Bochum, Universitätsstr. 150, D-44801 Bochum, Germany
| | - Peter Sandner
- Pharmaceuticals, Research and Early Development, Pharma Research Center, Bayer AG, Aprather Weg 18a, D-42096 Wuppertal, Germany
- Institute of Pharmacology, Hannover Medical School, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany
| | - Achim Schmidtko
- Institute of Pharmacology and Clinical Pharmacy, Goethe University, Max-Von-Laue-Str. 9, D-60438 Frankfurt Am Main, Germany
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Zhao H, Wang H, Zhang M, Weng C, Liu Y, Yin Z. Chromatic pupillometry isolation and evaluation of intrinsically photosensitive retinal ganglion cell-driven pupillary light response in patients with retinitis pigmentosa. Front Hum Neurosci 2023; 17:1212398. [PMID: 37533585 PMCID: PMC10390747 DOI: 10.3389/fnhum.2023.1212398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Accepted: 07/05/2023] [Indexed: 08/04/2023] Open
Abstract
Purpose The pupil light response (PLR) is driven by rods, cones, and intrinsically photosensitive retinal ganglion cells (ipRGCs). We aimed to isolate ipRGC-driven pupil responses using chromatic pupillometry and to determine the effect of advanced retinitis pigmentosa (RP) on ipRGC function. Methods A total of 100 eyes from 67 patients with advanced RP and 18 healthy controls (HCs) were included. Patients were divided into groups according to severity of visual impairment: no light perception (NLP, 9 eyes), light perception (LP, 19 eyes), faint form perception (FFP, 34 eyes), or form perception (FP, 38 eyes). Pupil responses to rod-weighted (487 nm, -1 log cd/m2, 1 s), cone-weighted (630 nm, 2 log cd/m2, 1 s), and ipRGC-weighted (487 nm, 2 log cd/m2, 1 s) stimuli were recorded. ipRGC function was evaluated by the postillumination pupil response (PIPR) and three metrics of pupil kinetics: maximal contraction velocity (MCV), contraction duration, and maximum dilation velocity (MDV). Results We found a slow, sustained PLR response to the ipRGC-weighted stimulus in most patients with NLP (8/9), but these patients had no detectable rod- or cone-driven PLR. The ipRGC-driven PLR had an MCV of 0.269 ± 0.150%/s and contraction duration of 2.562 ± 0.902 s, both of which were significantly lower than those of the rod and cone responses. The PIPRs of the RP groups did not decrease compared with those of the HCs group and were even enhanced in the LP group. At advanced stages, ipRGC responses gradually became the main component of the PLR. Conclusion Chromatic pupillometry successfully isolated an ipRGC-driven PLR in patients with advanced RP. This PLR remained stable and gradually became the main driver of pupil contraction in more advanced cases of RP. Here, we present baseline data on ipRGC function; we expect these findings to contribute to evaluating and screening candidates for novel therapies.
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Affiliation(s)
- He Zhao
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Hao Wang
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Minfang Zhang
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Chuanhuang Weng
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Yong Liu
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Zhengqin Yin
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
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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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6
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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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7
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Scalabrino ML, Thapa M, Wang T, Sampath AP, Chen J, Field GD. Late gene therapy limits the restoration of retinal function in a mouse model of retinitis pigmentosa. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.07.536035. [PMID: 37066264 PMCID: PMC10104154 DOI: 10.1101/2023.04.07.536035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Retinitis pigmentosa is an inherited photoreceptor degeneration that begins with rod loss followed by cone loss and eventual blindness. Gene therapies are being developed, but it is unknown how retinal function depends on the time of intervention. To uncover this dependence, we utilized a mouse model of retinitis pigmentosa capable of artificial genetic rescue. This model enables a benchmark of best-case gene therapy by removing the variables that complicate the ability to answer this vital question. Complete genetic rescue was performed at 25%, 50%, and 70% rod loss (early, mid and late, respectively). Early and mid treatment restored retinal function to near wild-type levels, specifically the sensitivity and signal fidelity of retinal ganglion cells (RGCs), the 'output' neurons of the retina. However, some anatomical defects persisted. Late treatment retinas exhibited continued, albeit slowed, loss of sensitivity and signal fidelity among RGCs, as well as persistent gliosis. We conclude that gene replacement therapies delivered after 50% rod loss are unlikely to restore visual function to normal. This is critical information for administering gene therapies to rescue vision.
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Affiliation(s)
- Miranda L Scalabrino
- Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles CA
- Department of Neurobiology, Duke University School of Medicine, Durham NC
| | - Mishek Thapa
- Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles CA
- Department of Neurobiology, Duke University School of Medicine, Durham NC
| | - Tian Wang
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles CA
| | - Alapakkam P Sampath
- Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles CA
| | - Jeannie Chen
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles CA
| | - Greg D Field
- Stein Eye Institute, Department of Ophthalmology, University of California, Los Angeles CA
- Department of Neurobiology, Duke University School of Medicine, Durham NC
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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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Mutations within the cGMP-binding domain of CNGA1 causing autosomal recessive retinitis pigmentosa in human and animal model. Cell Death Dis 2022; 8:387. [PMID: 36115851 PMCID: PMC9482621 DOI: 10.1038/s41420-022-01185-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 09/05/2022] [Accepted: 09/06/2022] [Indexed: 11/08/2022]
Abstract
Retinitis pigmentosa is a group of progressive inherited retinal dystrophies that may present clinically as part of a syndromic entity or as an isolated (nonsyndromic) manifestation. In an Indian family suffering from retinitis pigmentosa, we identified a missense variation in CNGA1 affecting the cyclic nucleotide binding domain (CNBD) and characterized a mouse model developed with mutated CNBD. A gene panel analysis comprising 105 known RP genes was used to analyze a family with autosomal-recessive retinitis pigmentosa (arRP) and revealed that CNGA1 was affected. From sperm samples of ENU mutagenesis derived F1 mice, we re-derived a mutant with a Cnga1 mutation. Homozygous mutant mice, developing retinal degeneration, were examined for morphological and functional consequences of the mutation. In the family, we identified a rare CNGA1 variant (NM_001379270.1) c.1525 G > A; (p.Gly509Arg), which co-segregated among the affected family members. Homozygous Cnga1 mice harboring a (ENSMUST00000087213.12) c.1526 A > G (p.Tyr509Cys) mutation showed progressive degeneration in the retinal photoreceptors from 8 weeks on. This study supports a role for CNGA1 as a disease gene for arRP and provides new insights on the pathobiology of cGMP-binding domain mutations in CNGA1-RP.
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10
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Wang H, Ouyang W, Liu Y, Zhang M, Zhao H, Wang J, Yin Z. Visual task-related functional and structural magnetic resonance imaging for the objective quantitation of visual function in patients with advanced retinitis pigmentosa. Front Aging Neurosci 2022; 14:825204. [PMID: 36034150 PMCID: PMC9416479 DOI: 10.3389/fnagi.2022.825204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Accepted: 06/28/2022] [Indexed: 11/22/2022] Open
Abstract
Purpose The objective quantitation of visual function in patients with advanced retinitis pigmentosa (RP) presents a difficult challenge due to the weak visual function of these patients. This study utilized magnetic resonance imaging (MRI) to assess the function and structure of the visual cortex (VC) in patients with RP and quantitatively categorize them. Materials and Methods Twenty-three patients with RP and ten healthy controls (HCs) were enrolled for MRI examinations. The patients were divided into form perception (FP) and no form perception (NFP) groups. Participants underwent structural MRI scans, and two visual task functional MRI scans were performed using stimuli, including white flash and black and white checkerboard patterns. Eight regions of interest (ROIs) were studied. In structural MRI, the gray matter volume (GMV) was compared in the ROIs. In the two visual tasks, the response intensity and functional connectivity (FC) of ROIs were also compared separately. Correlation analysis was performed to explore the correlations between the structural and functional parameters. Results In the structural analysis, the GMV in Brodmann areas 17, 18, and 19 of the FP and NFP groups was significantly lower than that of HCs. Regarding the functional data, the response intensity in the VC of both the FP and NFP groups was significantly lower than that in HCs. The response in Brodmann areas 17, 18, and 19 obtained using the pattern stimulus was significantly lower in the NFP group than in the FP group. For the FC comparison, the FP and NFP groups exhibited significantly lower values in several pathways than the HCs, and FC in the ipsilateral V1–contralateral V1 pathway in the flash task was significantly lower in the NFP group than in the FP group. A positive correlation between response intensity and GMV was observed in Brodmann areas 17, 18, and 19 in both flash and pattern visual tasks. Conclusion Magnetic resonance imaging was an effective tool to objectively and quantitatively evaluate the visual function of patients with advanced RP. Response intensity and FC were effective parameters to distinguish FP and NFP patients. A positive correlation between response intensity and GMV was observed in the VC.
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Affiliation(s)
- Hao Wang
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Wangbin Ouyang
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Yong Liu
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Minfang Zhang
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - He Zhao
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
| | - Jian Wang
- Department of Radiology, Southwest Hospital, Army Medical University, Chongqing, China
- *Correspondence: Jian Wang,
| | - Zhengqin Yin
- Southwest Hospital/Southwest Eye Hospital, Army Medical University, Chongqing, China
- Key Lab of Visual Damage and Regeneration and Restoration of Chongqing, Chongqing, China
- Zhengqin Yin,
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