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Huang M, Chow CH, Gurdita A, Harada H, Pham Truong VQB, Eide S, Sun HS, Feng ZP, Monnier PP, Wallace VA, Sugita S. SNAP-25, but not SNAP-23, is essential for photoreceptor development, survival, and function in mice. Commun Biol 2024; 7:34. [PMID: 38182732 PMCID: PMC10770054 DOI: 10.1038/s42003-023-05760-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Accepted: 12/29/2023] [Indexed: 01/07/2024] Open
Abstract
SNARE-mediated vesicular transport is thought to play roles in photoreceptor glutamate exocytosis and photopigment delivery. However, the functions of Synaptosomal-associated protein (SNAP) isoforms in photoreceptors are unknown. Here, we revisit the expression of SNAP-23 and SNAP-25 and generate photoreceptor-specific knockout mice to investigate their roles. Although we find that SNAP-23 shows weak mRNA expression in photoreceptors, SNAP-23 removal does not affect retinal morphology or vision. SNAP-25 mRNA is developmentally regulated and undergoes mRNA trafficking to photoreceptor inner segments at postnatal day 9 (P9). SNAP-25 knockout photoreceptors develop normally until P9 but degenerate by P14 resulting in severe retinal thinning. Photoreceptor loss in SNAP-25 knockout mice is associated with abolished electroretinograms and vision loss. We find mistrafficked photopigments, enlarged synaptic vesicles, and abnormal synaptic ribbons which potentially underlie photoreceptor degeneration. Our results conclude that SNAP-25, but not SNAP-23, mediates photopigment delivery and synaptic functioning required for photoreceptor development, survival, and function.
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Affiliation(s)
- Mengjia Huang
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Chun Hin Chow
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Akshay Gurdita
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Donald K. Johnson Eye Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
| | - Hidekiyo Harada
- Donald K. Johnson Eye Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
| | - Victor Q B Pham Truong
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Donald K. Johnson Eye Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
| | - Sarah Eide
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Hong-Shuo Sun
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Department of Anatomy, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Zhong-Ping Feng
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Philippe P Monnier
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Donald K. Johnson Eye Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
- Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, ON, M5T 3A9, Canada
| | - Valerie A Wallace
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ON, M5S 1A8, Canada
- Donald K. Johnson Eye Institute, University Health Network, Toronto, ON, M5T 0S8, Canada
- Department of Ophthalmology & Vision Sciences, University of Toronto, Toronto, ON, M5T 3A9, Canada
| | - Shuzo Sugita
- Division of Experimental & Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ON, M5T 0S8, Canada.
- Department of Physiology, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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Gurdita A, Pham Truong VQB, Dolati P, Juric M, Tachibana N, Liu ZC, Ortín-Martínez A, Ibrahimi M, Pokrajac NT, Comanita L, Pacal M, Huang M, Sugita S, Bremner R, Wallace VA. Progenitor division and cell autonomous neurosecretion are required for rod photoreceptor sublaminar positioning. Proc Natl Acad Sci U S A 2023; 120:e2308204120. [PMID: 37812728 PMCID: PMC10589646 DOI: 10.1073/pnas.2308204120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Accepted: 09/06/2023] [Indexed: 10/11/2023] Open
Abstract
Migration is essential for the laminar stratification and connectivity of neurons in the central nervous system. In the retina, photoreceptors (PRs) migrate to positions according to birthdate, with early-born cells localizing to the basal-most side of the outer nuclear layer. It was proposed that apical progenitor mitoses physically drive these basal translocations non-cell autonomously, but direct evidence is lacking, and whether other mechanisms participate is unknown. Here, combining loss- or gain-of-function assays to manipulate cell cycle regulators (Sonic hedgehog, Cdkn1a/p21) with an in vivo lentiviral labelling strategy, we demonstrate that progenitor division is one of two forces driving basal translocation of rod soma. Indeed, replacing Shh activity rescues abnormal rod translocation in retinal explants. Unexpectedly, we show that rod differentiation also promotes rod soma translocation. While outer segment function or formation is dispensable, Crx and SNARE-dependent synaptic function are essential. Thus, both non-cell and cell autonomous mechanisms underpin PR soma sublaminar positioning in the mammalian retina.
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Affiliation(s)
- Akshay Gurdita
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ONM5S 1A8, Canada
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ONM5T 2S8, Canada
| | - Victor Q. B. Pham Truong
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ONM5S 1A8, Canada
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ONM5T 2S8, Canada
| | - Parnian Dolati
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ONM5S 1A8, Canada
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ONM5T 2S8, Canada
| | - Matey Juric
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ONM5T 2S8, Canada
| | - Nobuhiko Tachibana
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ONM5T 2S8, Canada
| | - Zhongda C. Liu
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ONM5T 2S8, Canada
| | - Arturo Ortín-Martínez
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ONM5T 2S8, Canada
| | - Mostafa Ibrahimi
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ONM5S 1A8, Canada
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ONM5T 2S8, Canada
| | - Nenad T. Pokrajac
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ONM5S 1A8, Canada
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ONM5T 2S8, Canada
| | - Lacrimioara Comanita
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ONM5T 2S8, Canada
| | - Marek Pacal
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ONM5G 1X5, Canada
| | - Mengjia Huang
- Division of Experimental and Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ONM5T 2S8, Canada
- Department of Physiology, University of Toronto, Toronto, ONM5S 1A8, Canada
| | - Shuzo Sugita
- Division of Experimental and Translational Neuroscience, Krembil Brain Institute, University Health Network, Toronto, ONM5T 2S8, Canada
- Department of Physiology, University of Toronto, Toronto, ONM5S 1A8, Canada
| | - Rod Bremner
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ONM5S 1A8, Canada
- Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ONM5G 1X5, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ONM5T 3A9, Canada
| | - Valerie A. Wallace
- Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, ONM5S 1A8, Canada
- Donald K. Johnson Eye Institute, Krembil Research Institute, University Health Network, Toronto, ONM5T 2S8, Canada
- Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ONM5T 3A9, Canada
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