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Zhou X, Zhao L, Wang C, Sun W, Jia B, Li D, Fu J. Diverse functions and pathogenetic role of Crumbs in retinopathy. Cell Commun Signal 2024; 22:290. [PMID: 38802833 PMCID: PMC11129452 DOI: 10.1186/s12964-024-01673-z] [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: 02/13/2024] [Accepted: 05/20/2024] [Indexed: 05/29/2024] Open
Abstract
The Crumbs protein (CRB) family plays a crucial role in maintaining the apical-basal polarity and integrity of embryonic epithelia. The family comprises different isoforms in different animals and possesses diverse structural, localization, and functional characteristics. Mutations in the human CRB1 or CRB2 gene may lead to a broad spectrum of retinal dystrophies. Various CRB-associated experimental models have recently provided mechanistic insights into human CRB-associated retinopathies. The knowledge obtained from these models corroborates the importance of CRB in retinal development and maintenance. Therefore, complete elucidation of these models can provide excellent therapeutic prospects for human CRB-associated retinopathies. In this review, we summarize the current animal models and human-derived models of different CRB family members and describe the main characteristics of their retinal phenotypes.
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Affiliation(s)
- Xuebin Zhou
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130000, China
| | - Liangliang Zhao
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130000, China
| | - Chenguang Wang
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130000, China
| | - Wei Sun
- College of Basic Medical Sciences, Jilin University, Changchun, 130000, China
| | - Bo Jia
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130000, China
| | - Dan Li
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130000, China
| | - Jinling Fu
- Department of Ophthalmology, The Second Hospital of Jilin University, Changchun, 130000, China.
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Wright GA, Rodriguez-Martinez AC, Conn H, Matarin M, Thompson P, Moore AT, Ba-Abbad R, Webster AR, Moosajee M. Enhanced Learning and Memory in Patients with CRB1 Retinopathy. Genes (Basel) 2024; 15:660. [PMID: 38927596 PMCID: PMC11203261 DOI: 10.3390/genes15060660] [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: 05/04/2024] [Revised: 05/20/2024] [Accepted: 05/21/2024] [Indexed: 06/28/2024] Open
Abstract
Mutations in the CRB1 gene are associated with a diverse spectrum of retinopathies with phenotypic variability causing severe visual impairment. The CRB1 gene has a role in retinal development and is expressed in the cerebral cortex and hippocampus, but its role in cognition has not been described before. This study compares cognitive function in CRB1 retinopathy individuals with subjects with other retinopathies and the normal population. METHODS Neuropsychological tests of cognitive function were used to test individuals with CRB1 and non-CRB1 retinopathies and compare results with a standardised normative dataset. RESULTS CRB1 retinopathy subjects significantly outperformed those with non-CRB1 retinopathy in list learning tasks of immediate (p = 0.001) and delayed memory (p = 0.007), tests of semantic verbal fluency (p = 0.017), verbal IQ digit span subtest (p = 0.037), and estimation test of higher execution function (p = 0.020) but not in the remaining tests of cognitive function (p > 0.05). CRB1 retinopathy subjects scored significantly higher than the normal population in all areas of memory testing (p < 0.05) and overall verbal IQ tests (p = 0.0012). Non-CRB1 retinopathy subjects scored significantly higher than the normal population in story recall, verbal fluency, and overall verbal IQ tests (p = 0.0016). CONCLUSIONS Subjects with CRB1 retinopathy may have enhanced cognitive function in areas of memory and learning. Further work is required to understand the role of CRB1 in cognition.
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Affiliation(s)
- Genevieve A. Wright
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK; (G.A.W.); (A.C.R.-M.); (A.T.M.); (R.B.-A.); (A.R.W.)
- Institute of Ophthalmology, University College London (UCL), London EC1V 9EL, UK
| | - Ana Catalina Rodriguez-Martinez
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK; (G.A.W.); (A.C.R.-M.); (A.T.M.); (R.B.-A.); (A.R.W.)
- Institute of Ophthalmology, University College London (UCL), London EC1V 9EL, UK
| | - Hanne Conn
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London Hospitals (UCLH), National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK; (H.C.); (M.M.); (P.T.)
| | - Mar Matarin
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London Hospitals (UCLH), National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK; (H.C.); (M.M.); (P.T.)
| | - Pamela Thompson
- Department of Clinical and Experimental Epilepsy, Institute of Neurology, University College London Hospitals (UCLH), National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK; (H.C.); (M.M.); (P.T.)
| | - Anthony T. Moore
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK; (G.A.W.); (A.C.R.-M.); (A.T.M.); (R.B.-A.); (A.R.W.)
- Institute of Ophthalmology, University College London (UCL), London EC1V 9EL, UK
| | - Rola Ba-Abbad
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK; (G.A.W.); (A.C.R.-M.); (A.T.M.); (R.B.-A.); (A.R.W.)
- Institute of Ophthalmology, University College London (UCL), London EC1V 9EL, UK
| | - Andrew R. Webster
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK; (G.A.W.); (A.C.R.-M.); (A.T.M.); (R.B.-A.); (A.R.W.)
- Institute of Ophthalmology, University College London (UCL), London EC1V 9EL, UK
| | - Mariya Moosajee
- Moorfields Eye Hospital NHS Foundation Trust, London EC1V 2PD, UK; (G.A.W.); (A.C.R.-M.); (A.T.M.); (R.B.-A.); (A.R.W.)
- Institute of Ophthalmology, University College London (UCL), London EC1V 9EL, UK
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Möller-Kerutt A, Rodriguez-Gatica JE, Wacker K, Bhatia R, Siebrasse JP, Boon N, Van Marck V, Boor P, Kubitscheck U, Wijnholds J, Pavenstädt H, Weide T. Crumbs2 Is an Essential Slit Diaphragm Protein of the Renal Filtration Barrier. J Am Soc Nephrol 2021; 32:1053-1070. [PMID: 33687977 PMCID: PMC8259666 DOI: 10.1681/asn.2020040501] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 12/28/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Crumbs2 is expressed at embryonic stages as well as in the retina, brain, and glomerular podocytes. Recent studies identified CRB2 mutations as a novel cause of steroid-resistant nephrotic syndrome (SRNS). METHODS To study the function of Crb2 at the renal filtration barrier, mice lacking Crb2 exclusively in podocytes were generated. Gene expression and histologic studies as well as transmission and scanning electron microscopy were used to analyze these Crb2podKO knockout mice and their littermate controls. Furthermore, high-resolution expansion microscopy was used to investigate Crb2 distribution in murine glomeruli. For pull-down experiments, live cell imaging, and transcriptome analyses, cell lines were applied that inducibly express fluorescent protein-tagged CRB2 wild type and mutants. RESULTS Crb2podKO mice developed proteinuria directly after birth that preceded a prominent development of disordered and effaced foot processes, upregulation of renal injury and inflammatory markers, and glomerulosclerosis. Pull-down assays revealed an interaction of CRB2 with Nephrin, mediated by their extracellular domains. Expansion microscopy showed that in mice glomeruli, Crb2 and Nephrin are organized in adjacent clusters. SRNS-associated CRB2 protein variants and a mutant that lacks a putative conserved O-glycosylation site were not transported to the cell surface. Instead, mutants accumulated in the ER, showed altered glycosylation pattern, and triggered an ER stress response. CONCLUSIONS Crb2 is an essential component of the podocyte's slit diaphragm, interacting with Nephrin. Loss of slit diaphragm targeting and increasing ER stress are pivotal factors for onset and progression of CRB2-related SRNS.
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Affiliation(s)
- Annika Möller-Kerutt
- Internal Medicine D, Department of Molecular Nephrology, University Hospital of Muenster, Muenster, Germany
| | - Juan E. Rodriguez-Gatica
- Institute of Physical and Theoretical Chemistry, Department of Biophysical Chemistry, Rheinische Friedrich Wilhelms University Bonn, Bonn, Germany
| | - Karin Wacker
- Internal Medicine D, Department of Molecular Nephrology, University Hospital of Muenster, Muenster, Germany
| | - Rohan Bhatia
- Institute of Physical and Theoretical Chemistry, Department of Biophysical Chemistry, Rheinische Friedrich Wilhelms University Bonn, Bonn, Germany
| | - Jan-Peter Siebrasse
- Institute of Physical and Theoretical Chemistry, Department of Biophysical Chemistry, Rheinische Friedrich Wilhelms University Bonn, Bonn, Germany
| | - Nanda Boon
- Leiden University Medical Center, Department of Ophthalmology, Leiden, The Netherlands
| | - Veerle Van Marck
- Gerhard-Domagk Institute of Pathology, University Hospital of Muenster, Muenster, Germany
| | - Peter Boor
- Institute of Pathology, Department of Nephrology and Immunology, RWTH Aachen University Hospital, Aachen, Germany,The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Ulrich Kubitscheck
- Institute of Physical and Theoretical Chemistry, Department of Biophysical Chemistry, Rheinische Friedrich Wilhelms University Bonn, Bonn, Germany
| | - Jan Wijnholds
- Leiden University Medical Center, Department of Ophthalmology, Leiden, The Netherlands
| | - Hermann Pavenstädt
- Internal Medicine D, Department of Molecular Nephrology, University Hospital of Muenster, Muenster, Germany
| | - Thomas Weide
- Internal Medicine D, Department of Molecular Nephrology, University Hospital of Muenster, Muenster, Germany
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Burger CA, Jiang D, Mackin RD, Samuel MA. Development and maintenance of vision's first synapse. Dev Biol 2021; 476:218-239. [PMID: 33848537 DOI: 10.1016/j.ydbio.2021.04.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Revised: 04/02/2021] [Accepted: 04/03/2021] [Indexed: 12/21/2022]
Abstract
Synapses in the outer retina are the first information relay points in vision. Here, photoreceptors form synapses onto two types of interneurons, bipolar cells and horizontal cells. Because outer retina synapses are particularly large and highly ordered, they have been a useful system for the discovery of mechanisms underlying synapse specificity and maintenance. Understanding these processes is critical to efforts aimed at restoring visual function through repairing or replacing neurons and promoting their connectivity. We review outer retina neuron synapse architecture, neural migration modes, and the cellular and molecular pathways that play key roles in the development and maintenance of these connections. We further discuss how these mechanisms may impact connectivity in the retina.
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Affiliation(s)
- Courtney A Burger
- Huffington Center on Aging, Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Danye Jiang
- Huffington Center on Aging, Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Robert D Mackin
- Huffington Center on Aging, Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Melanie A Samuel
- Huffington Center on Aging, Department of Neuroscience, Baylor College of Medicine, Houston, TX, 77030, USA.
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Buck TM, Vos RM, Alves CH, Wijnholds J. AAV- CRB2 protects against vision loss in an inducible CRB1 retinitis pigmentosa mouse model. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2020; 20:423-441. [PMID: 33575434 PMCID: PMC7848734 DOI: 10.1016/j.omtm.2020.12.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 12/21/2020] [Indexed: 01/31/2023]
Abstract
Loss of Crumbs homolog 1 (CRB1) or CRB2 proteins in Müller cells or photoreceptors in the mouse retina results in a CRB dose-dependent retinal phenotype. In this study, we present a novel Müller cell-specific Crb1KOCrb2LowMGC retinitis pigmentosa mouse model (complete loss of CRB1 and reduced levels of CRB2 specifically in Müller cells). The Crb double mutant mice showed deficits in electroretinography, optokinetic head tracking, and retinal morphology. Exposure of retinas to low levels of dl-α-aminoadipate acid induced gliosis and retinal disorganization in Crb1KOCrb2LowMGC retinas but not in wild-type or Crb1-deficient retinas. Crb1KOCrb2LowMGC mice showed a substantial decrease in inner/outer photoreceptor segment length and optokinetic head-tracking response. Intravitreal application of rAAV vectors expressing human CRB2 (hCRB2) in Müller cells of Crb1KOCrb2LowMGC mice subsequently exposed to low levels of dl-α-aminoadipate acid prevented loss of vision, whereas recombinant adeno-associated viral (rAAV) vectors expressing human CRB1 (hCRB1) did not. Both rAAV vectors partially protected the morphology of the retina. The results suggest that hCRB expression in Müller cells is vital for control of retinal cell adhesion at the outer limiting membrane, and that the rAAV-cytomegalovirus (CMV)-hCRB2 vector is more potent than rAAV-minimal CMV (CMVmin)-hCRB1 in protection against loss of vision.
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Affiliation(s)
- Thilo M Buck
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, the Netherlands
| | - Rogier M Vos
- Netherlands Institute of Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), 1105 BA Amsterdam, the Netherlands
| | - C Henrique Alves
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, the Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, the Netherlands.,Netherlands Institute of Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), 1105 BA Amsterdam, the Netherlands
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Cho SH, Nahar A, Kim JH, Lee M, Kozmik Z, Kim S. Targeted deletion of Crb1/Crb2 in the optic vesicle models key features of leber congenital amaurosis 8. Dev Biol 2019; 453:141-154. [PMID: 31145883 DOI: 10.1016/j.ydbio.2019.05.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 05/20/2019] [Accepted: 05/21/2019] [Indexed: 01/01/2023]
Abstract
The Crb1 and 2 (Crumbs homolog 1 & 2) genes encode large, single-pass transmembrane proteins essential for the apicobasal polarity and adhesion of epithelial cells. Crb1 mutations cause degenerative retinal diseases in humans, including Leber congenital amaurosis type 8 (LCA8) and retinitis pigmentosa type 12 (RP12). In LCA8, impaired photoreceptor development and/or survival is thought to cause blindness during early infancy, whereas, in RP12, progressive photoreceptor degeneration damages peripheral vision later in life. There are multiple animal models of RP12 pathology, but no experimental model of LCA8 recapitulates the full spectrum of its pathological features. To generate a mouse model of LCA8 and identify the functions of Crb1/2 in developing ocular tissues, we used an mRx-Cre driver to generate allelic combinations that enabled conditional gene ablation from the optic vesicle stage. In this series only Crb1/2 double knockout (dKO) mice exhibited characteristics of human LCA8 disease: locally thickened retina with spots devoid of cells, aberrant positioning of retinal cells, severely disrupted lamination, and depigmented retinal-pigmented epithelium. Retinal defects antedated E12.5, which is far earlier than the stage at which photoreceptor cells mainly differentiate. Most remarkably, Crb1/Crb2 dKO showed a severely attenuated electroretinogram at the eye opening stage. These results suggest that human LCA8 can be modeled in the mouse by simultaneously ablating Crb1/2 from the beginning of eye development. Importantly, they also indicate that LCA8 is caused by malfunction of retinal progenitor cells during early ocular development rather than by defective photoreceptor-Muller glial interaction, a mechanism proposed for RP12.
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Affiliation(s)
- Seo-Hee Cho
- Shriners Hospitals Pediatric Research Center, Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA.
| | - Ankur Nahar
- Shriners Hospitals Pediatric Research Center, Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Ji Hyang Kim
- Shriners Hospitals Pediatric Research Center, Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Matthew Lee
- Shriners Hospitals Pediatric Research Center, Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
| | - Zbynek Kozmik
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic
| | - Seonhee Kim
- Shriners Hospitals Pediatric Research Center, Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, 19140, USA
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