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Han S, Wang Q, Cheng M, Hu Y, Liu P, Hou W, Liang L. The effects of ush2a gene knockout on vesicle transport in photoreceptors. Gene 2024; 892:147885. [PMID: 37813209 DOI: 10.1016/j.gene.2023.147885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 09/25/2023] [Accepted: 10/06/2023] [Indexed: 10/11/2023]
Abstract
USH2A (Usher syndrome type 2A) gene mutations are the predominant cause of Usher syndrome type 2, characterized by sensorineural hearing loss and retinitis pigmentosa (RP), and also significant contributors to non-syndromic RP. To date, there is a lack of definitive therapeutic interventions to mitigate the associated disorders caused by USH2A mutations, and the precise pathogenic mechanisms underlying their onset remain unclear. In the present study, we utilized the ush2a knockout zebrafish model to investigate the pathological mechanisms of RP. In late-stage ush2a-/- zebrafish, the outer segments of rods displayed shortened length and decreased number. Anomalous vesicle accumulation was observed at the junction between the inner and outer segments, accompanied by reduced expression and structural damage of actin filaments in the photoreceptor cells. Furthermore, we discovered that Rab8 expression was downregulated and exhibited aberrant localization in ush2a-/- zebrafish. Additionally, we identified an interaction between USH2A and Rab8. Therefore, the knockout of ush2a may potentially affect vesicle transport through the regulation of Rab8, providing a novel target for maintaining the survival of photoreceptor cells. These findings also contribute to our understanding of the potential molecular pathogenesis underlying RP caused by USH2A gene mutations.
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Affiliation(s)
- Shanshan Han
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China
| | - Qiong Wang
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China
| | - Meiqi Cheng
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China
| | - Yue Hu
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China
| | - Pei Liu
- Hubei Key Laboratory of Tumor Microenvironment and Immunotherapy, China Three Gorges University, Yichang 443002, Hubei, China; College of Basic Medical Sciences, China Three Gorges University, Yichang 443002, Hubei, China
| | - Wanle Hou
- Department of Clinical Laboratory, the First Hospital of Laohekou City, Laohekou 441800, Hubei, China.
| | - Liang Liang
- Department of Ophthalmology, the First Clinical Hospital of China Three Gorges University, Yichang 443003, Hubei, China.
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Veleri S, Nellissery J, Mishra B, Manjunath SH, Brooks MJ, Dong L, Nagashima K, Qian H, Gao C, Sergeev YV, Huang XF, Qu J, Lu F, Cideciyan AV, Li T, Jin ZB, Fariss RN, Ratnapriya R, Jacobson SG, Swaroop A. REEP6 mediates trafficking of a subset of Clathrin-coated vesicles and is critical for rod photoreceptor function and survival. Hum Mol Genet 2017; 26:2218-2230. [PMID: 28369466 PMCID: PMC5458339 DOI: 10.1093/hmg/ddx111] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Accepted: 03/16/2017] [Indexed: 01/20/2023] Open
Abstract
In retinal photoreceptors, vectorial transport of cargo is critical for transduction of visual signals, and defects in intracellular trafficking can lead to photoreceptor degeneration and vision impairment. Molecular signatures associated with routing of transport vesicles in photoreceptors are poorly understood. We previously reported the identification of a novel rod photoreceptor specific isoform of Receptor Expression Enhancing Protein (REEP) 6, which belongs to a family of proteins involved in intracellular transport of receptors to the plasma membrane. Here we show that loss of REEP6 in mice (Reep6−/−) results in progressive retinal degeneration. Rod photoreceptor dysfunction is observed in Reep6−/− mice as early as one month of age and associated with aberrant accumulation of vacuole-like structures at the apical inner segment and reduction in selected rod phototransduction proteins. We demonstrate that REEP6 is detected in a subset of Clathrin-coated vesicles and interacts with the t-SNARE, Syntaxin3. In concordance with the rod degeneration phenotype in Reep6−/− mice, whole exome sequencing identified homozygous REEP6-E75K mutation in two retinitis pigmentosa families of different ethnicities. Our studies suggest a critical function of REEP6 in trafficking of cargo via a subset of Clathrin-coated vesicles to selected membrane sites in retinal rod photoreceptors.
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Affiliation(s)
- Shobi Veleri
- Neurobiology Neurodegeneration and Repair Laboratory
| | | | | | | | | | - Lijin Dong
- Genetic Engineering Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Kunio Nagashima
- Frederick National Laboratory for Cancer Research, Frederick, MD 21701, USA
| | - Haohua Qian
- Visual Function Core, 5Biological Imaging Core
| | - Chun Gao
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Yuri V Sergeev
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Xiu-Feng Huang
- The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and
| | - Jia Qu
- The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and
| | - Fan Lu
- The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and
| | - Artur V Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Tiansen Li
- Neurobiology Neurodegeneration and Repair Laboratory
| | - Zi-Bing Jin
- The Eye Hospital of Wenzhou Medical University, Wenzhou 325027, China and
| | - Robert N Fariss
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | | | - Samuel G Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Anand Swaroop
- Neurobiology Neurodegeneration and Repair Laboratory
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