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Stehle IF, Imventarza JA, Woerz F, Hoffmann F, Boldt K, Beyer T, Quinn PM, Ueffing M. Human CRB1 and CRB2 form homo- and heteromeric protein complexes in the retina. Life Sci Alliance 2024; 7:e202302440. [PMID: 38570189 PMCID: PMC10992996 DOI: 10.26508/lsa.202302440] [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] [Received: 10/17/2023] [Revised: 03/26/2024] [Accepted: 03/26/2024] [Indexed: 04/05/2024] Open
Abstract
Crumbs homolog 1 (CRB1) is one of the key genes linked to retinitis pigmentosa and Leber congenital amaurosis, which are characterized by a high clinical heterogeneity. The Crumbs family member CRB2 has a similar protein structure to CRB1, and in zebrafish, Crb2 has been shown to interact through the extracellular domain. Here, we show that CRB1 and CRB2 co-localize in the human retina and human iPSC-derived retinal organoids. In retina-specific pull-downs, CRB1 was enriched in CRB2 samples, supporting a CRB1-CRB2 interaction. Furthermore, novel interactors of the crumbs complex were identified, representing a retina-derived protein interaction network. Using co-immunoprecipitation, we further demonstrate that human canonical CRB1 interacts with CRB1 and CRB2, but not with CRB3, which lacks an extracellular domain. Next, we explored how missense mutations in the extracellular domain affect CRB1-CRB2 interactions. We observed no or a mild loss of CRB1-CRB2 interaction, when interrogating various CRB1 or CRB2 missense mutants in vitro. Taken together, our results show a stable interaction of human canonical CRB2 and CRB1 in the retina.
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Affiliation(s)
- Isabel F Stehle
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Joel A Imventarza
- Department of Ophthalmology, Vagelos College of Physicians & Surgeons, Columbia University; New York, NY, USA
| | - Franziska Woerz
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Felix Hoffmann
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Karsten Boldt
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Tina Beyer
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Peter Mj Quinn
- Department of Ophthalmology, Vagelos College of Physicians & Surgeons, Columbia University; New York, NY, USA
| | - Marius Ueffing
- https://ror.org/03a1kwz48 Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Tübingen, Germany
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2
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Peng S, Li JJ, Song W, Li Y, Zeng L, Liang Q, Wen X, Shang H, Liu K, Peng P, Xue W, Zou B, Yang L, Liang J, Zhang Z, Guo S, Chen T, Li W, Jin M, Xing XB, Wan P, Liu C, Lin H, Wei H, Lee RWJ, Zhang F, Wei L. CRB1-associated retinal degeneration is dependent on bacterial translocation from the gut. Cell 2024; 187:1387-1401.e13. [PMID: 38412859 DOI: 10.1016/j.cell.2024.01.040] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 07/07/2023] [Accepted: 01/25/2024] [Indexed: 02/29/2024]
Abstract
The Crumbs homolog 1 (CRB1) gene is associated with retinal degeneration, most commonly Leber congenital amaurosis (LCA) and retinitis pigmentosa (RP). Here, we demonstrate that murine retinas bearing the Rd8 mutation of Crb1 are characterized by the presence of intralesional bacteria. While normal CRB1 expression was enriched in the apical junctional complexes of retinal pigment epithelium and colonic enterocytes, Crb1 mutations dampened its expression at both sites. Consequent impairment of the outer blood retinal barrier and colonic intestinal epithelial barrier in Rd8 mice led to the translocation of intestinal bacteria from the lower gastrointestinal (GI) tract to the retina, resulting in secondary retinal degeneration. Either the depletion of bacteria systemically or the reintroduction of normal Crb1 expression colonically rescued Rd8-mutation-associated retinal degeneration without reversing the retinal barrier breach. Our data elucidate the pathogenesis of Crb1-mutation-associated retinal degenerations and suggest that antimicrobial agents have the potential to treat this devastating blinding disease.
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Affiliation(s)
- Shanzhen Peng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Jing Jing Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Wanying Song
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Ye Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Lei Zeng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Qiaoxing Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Xiaofeng Wen
- School of Pharmaceutical Sciences, Southern Medical University, Guangzhou 510000, China
| | - Haitao Shang
- Precision Medicine Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China
| | - Keli Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Peiyao Peng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Wei Xue
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Bin Zou
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Liu Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Juanran Liang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Zhihui Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China; Tianjin Medical University Eye Hospital, Eye Institute & School of Optometry and Ophthalmology, Tianjin 300384, China
| | - Shixin Guo
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Tingting Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Wenxuan Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China; Department of Biostatistics, Yale School of Public Health, New Haven, CT 06510, USA
| | - Ming Jin
- Department of Ophthalmology, China-Japan Friendship Hospital, Beijing 10029, China
| | - Xiang-Bin Xing
- Department of Gastroenterology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510000, China
| | - Pengxia Wan
- Department of Ophthalmology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510000, China
| | - Chunqiao Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Haotian Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China
| | - Hong Wei
- Precision Medicine Institute, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China.
| | - Richard W J Lee
- UCL Institute of Ophthalmology and Moorfields Eye Hospital NHS Foundation Trust, London, UK.
| | - Feng Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China.
| | - Lai Wei
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou 510060, China; Guangdong Provincial Key Laboratory of Allergy & Clinical Immunology, The Second Affiliated Hospital, Guangzhou Medical University, Guangzhou 510260, China; The First Affiliated Hospital, Department of Ophthalmology, University of South China, Hengyang 421001, Hunan, China.
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3
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Albakri A, Pisuchpen P, Capasso JE, Schneider A, Kopinsky S, Glaser T, Chiang JPW, Yomai AA, McNear D, Levin AV. Novel CRB1 pathogenic variant in Chuuk families with Leber congenital amaurosis. Am J Med Genet A 2023; 191:1007-1012. [PMID: 36595661 PMCID: PMC10262898 DOI: 10.1002/ajmg.a.63108] [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: 09/14/2022] [Revised: 11/13/2022] [Accepted: 11/15/2022] [Indexed: 01/05/2023]
Abstract
The purpose of this article is to determine the cause of Leber congenital amaurosis (LCA) in Chuuk state, Federated States of Micronesia (FSM). In this prospective observational case series, five patients with early-onset vision loss were examined in Chuuk state, FSM, during an ocular genetics visit to study the elevated incidence of microphthalmia. Because of their low vision these patients were incorrectly assumed to have microphthalmia. A complete ophthalmological exam established a clinical diagnosis of LCA. Candidate gene exons were sequenced with a targeted retinal dystrophy panel. Five subjects in three related families were diagnosed with LCA. All five were from Tonoas Island, within the Chuuk Lagoon, with ages ranging from 6 months to 16 years. DNA sequencing of affected individuals revealed a homozygous CRB1 NM_201253.3:c.3134del pathogenic variant, which was heterozygous in their parents. CRB1 genotypes were confirmed by a PCR restriction assay. We report identification of a founder pathogenic variant in CRB1 responsible for autosomal recessive LCA in this isolated community. This discovery will lead to appropriate recurrence risk counseling.
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Affiliation(s)
- Amani Albakri
- Pediatric and Ocular Genetics, Wills Eye Hospital, Philadelphia, Pennsylvania, USA
- Division of Pediatric Ophthalmology, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Phattrawan Pisuchpen
- Pediatric and Ocular Genetics, Wills Eye Hospital, Philadelphia, Pennsylvania, USA
- Department of Ophthalmology, Faculty of Medicine, Chulalongkorn University and King Chulalongkorn Memorial Hospital, the Thai Red Cross Society, Bangkok, Thailand
| | - Jenina E. Capasso
- Pediatric and Ocular Genetics, Wills Eye Hospital, Philadelphia, Pennsylvania, USA
| | - Adele Schneider
- Pediatric and Ocular Genetics, Wills Eye Hospital, Philadelphia, Pennsylvania, USA
- Division of Genetics, Einstein Healthcare Network, Philadelphia, Pennsylvania, USA
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Sarina Kopinsky
- Division of Genetics, Einstein Healthcare Network, Philadelphia, Pennsylvania, USA
| | - Tom Glaser
- Department of Cell Biology & Human Anatomy, University of California, Davis, California, USA
| | | | | | - Donna McNear
- Independent Educational Consultant, Cambridge, Minnesota, USA
| | - Alex V. Levin
- Pediatric and Ocular Genetics, Wills Eye Hospital, Philadelphia, Pennsylvania, USA
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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4
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Zebrafish: A Model to Study and Understand the Diabetic Nephropathy and Other Microvascular Complications of Type 2 Diabetes Mellitus. Vet Sci 2022; 9:vetsci9070312. [PMID: 35878329 PMCID: PMC9323928 DOI: 10.3390/vetsci9070312] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 06/14/2022] [Accepted: 06/16/2022] [Indexed: 12/02/2022] Open
Abstract
Simple Summary Diabetes is a chronic metabolic disease characterized by high blood glucose levels (hyperglycemia). Type 2 diabetes mellitus (T2DM) and its complications are a worldwide public health problem, affecting people from all developed and developing countries. Hyperglycemia can cause damage to the vascular system and dysfunction of organs, such as the kidneys, heart, retina of the eyes, and nerves. Diabetic nephropathy (DN) is one of the most severe micro-vascular complications, which can lead to ESRD (end-stage renal disease). Zebrafish are ideal for wide-scale analysis or screening, due to their small size, quick growth, transparent embryos, vast number of offspring, and gene similarity with humans, which combine to make zebrafish an ideal model for diabetes. The readily available tools for gene editing using morpholinos or CRISPR/Cas9, as well as chemical/drug therapy by microinjection or skin absorption, enable zebrafish diabetes mellitus models to be established in a number of ways. In this review, we emphasize the physiological and pathological processes relating to micro-vascular problems in zebrafish, as well as the many experimental zebrafish models used to research DN, and the DN-related outcomes and mechanisms observed in zebrafish. This study specifies the benefits and drawbacks and future perspective of using zebrafish as a disease model. Abstract Diabetes mellitus (DM) is a complicated metabolic illness that has had a worldwide impact and placed an unsustainable load on both developed and developing countries’ health care systems. According to the International Diabetes Federation, roughly 537 million individuals had diabetes in 2021, with type 2 diabetes mellitus accounting for the majority of cases (T2DM). T2DM is a chronic illness defined by insufficient insulin production from pancreatic islet cells. T2DM generates various micro and macrovascular problems, with diabetic nephropathy (DN) being one of the most serious microvascular consequences, and which can lead to end-stage renal disease. The zebrafish (Danio rerio) has set the way for its future as a disease model organism. As numerous essential developmental processes, such as glucose metabolism and reactive metabolite production pathways, have been identified in zebrafish that are comparable to those seen in humans, it is a good model for studying diabetes and its consequences. It also has many benefits over other vertebrate models, including the permeability of its embryos to small compounds, disease-driven therapeutic target selection, in vivo validation, and deconstruction of biological networks. The organism can also be utilized to investigate and understand the genetic abnormalities linked to the onset of diabetes problems. Zebrafish may be used to examine and visualize the growth, morphology, and function of organs under normal physiological and diabetic settings. The zebrafish has become one of the most useful models for studying DN, especially when combined with genetic alterations and/or mutant or transgenic fish lines. The significant advancements of CRISPR and next-generation sequencing technology for disease modelling in zebrafish, as well as developments in molecular and nano technologies, have advanced the understanding of the molecular mechanisms of several human diseases, including DN. In this review, we emphasize the physiological and pathological processes relating to microvascular problems in zebrafish, as well as the many experimental zebrafish models used to research DN, and the DN-related outcomes and mechanisms observed in zebrafish.
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Schellens R, de Vrieze E, Graave P, Broekman S, Nagel-Wolfrum K, Peters T, Kremer H, Collin RWJ, van Wijk E. Zebrafish as a Model to Evaluate a CRISPR/Cas9-Based Exon Excision Approach as a Future Treatment Option for EYS-Associated Retinitis Pigmentosa. Int J Mol Sci 2021; 22:ijms22179154. [PMID: 34502064 PMCID: PMC8431288 DOI: 10.3390/ijms22179154] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 08/18/2021] [Accepted: 08/18/2021] [Indexed: 12/26/2022] Open
Abstract
Retinitis pigmentosa (RP) is an inherited retinal disease (IRD) with an overall prevalence of 1 in 4000 individuals. Mutations in EYS (Eyes shut homolog) are among the most frequent causes of non-syndromic autosomal recessively inherited RP and act via a loss-of-function mechanism. In light of the recent successes for other IRDs, we investigated the therapeutic potential of exon skipping for EYS-associated RP. CRISPR/Cas9 was employed to generate zebrafish from which the region encompassing the orthologous exons 37-41 of human EYS (eys exons 40-44) was excised from the genome. The excision of these exons was predicted to maintain the open reading frame and to result in the removal of exactly one Laminin G and two EGF domains. Although the eysΔexon40-44 transcript was found at levels comparable to wild-type eys, and no unwanted off-target modifications were identified within the eys coding sequence after single-molecule sequencing, EysΔexon40-44 protein expression could not be detected. Visual motor response experiments revealed that eysΔexon40-44 larvae were visually impaired and histological analysis revealed a progressive degeneration of the retinal outer nuclear layer in these zebrafish. Altogether, the data obtained in our zebrafish model currently provide no indications for the skipping of EYS exons 37-41 as an effective future treatment strategy for EYS-associated RP.
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Affiliation(s)
- Renske Schellens
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
| | - Erik de Vrieze
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
| | - Pam Graave
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Sanne Broekman
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
| | - Kerstin Nagel-Wolfrum
- Institute for Molecular Physiology, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany;
- Institute for Developmental Biology and Neurobiology, Johannes Gutenberg-University Mainz, 55099 Mainz, Germany
| | - Theo Peters
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
| | - Hannie Kremer
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Rob W. J. Collin
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
- Department of Human Genetics, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands;
| | - Erwin van Wijk
- Department of Otorhinolaryngology, Radboud University Medical Center, 6525 GA Nijmegen, The Netherlands; (R.S.); (E.d.V.); (S.B.); (T.P.); (H.K.)
- Donders Institute for Brain Cognition and Behaviour, 6500 GL Nijmegen, The Netherlands;
- Correspondence:
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6
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Wang Y, Sun W, Xiao X, Li S, Jia X, Wang P, Zhang Q. Clinical and Genetic Analysis of 63 Families Demonstrating Early and Advanced Characteristic Fundus as the Signature of CRB1 Mutations. Am J Ophthalmol 2021; 223:160-168. [PMID: 33342761 DOI: 10.1016/j.ajo.2020.10.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/17/2020] [Accepted: 10/12/2020] [Indexed: 11/28/2022]
Abstract
PURPOSE To reveal the characteristics of ocular changes in patients with biallelic CRB1 mutations. DESIGN Comparative exome sequencing and retrospective case series on clinical data. METHODS Seventy-four patients from 63 families with biallelic potential pathogenic variants in CRB1 were selected from our in-house exome sequencing. The clinical data were reviewed and evaluated in detail, including best-corrected visual acuity, fundus photography, optical coherence tomography (OCT), and electroretinogram (ERG). RESULTS Biallelic CRB1 variants, involving 45 variants including 23 novel, were identified in 40 novel families based on exome sequencing. Analyzing clinical data of the 74 individuals from 63 families revealed the following CRB1-associated phenotypes: (1) early-onset reduced visual acuity with congenital nystagmus; (2) 2 types of characteristic retinal changes including yellowish geographic macular degeneration (YMD) or nummular pigment deposits (NPD) at posterior retina with bone-spicule pigmentation at midperipheral retina; (3) undetectable rod and cone responses on ERG; (4) cystoid macular edema or macular atrophy on OCT. YMD and NPD are unique and CRB1-associated. Long-term follow-up examination as well as age- and variant-dependent phenotypic analysis suggested YMD is the early fundus change that would gradually progress to NPD. CONCLUSIONS YMD and NPD are 2 major characteristic CRB1-associated fundus changes and the former one will advance to the latter with age. Recognizing such characteristic signs associated with biallelic CRB1 variants may be of value in areas without widespread access to genetic testing where a more targeted approach is needed and might be biomarkers for evaluation of effects for future intervention.
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Affiliation(s)
- Yingwei Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Wenmin Sun
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xueshan Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Shiqiang Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Xiaoyun Jia
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Panfeng Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Qingjiong Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
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7
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Sallum JMF, Motta FL, Arno G, Porto FBO, Resende RG, Belfort R. Clinical and molecular findings in a cohort of 152 Brazilian severe early onset inherited retinal dystrophy patients. AMERICAN JOURNAL OF MEDICAL GENETICS PART C-SEMINARS IN MEDICAL GENETICS 2020; 184:728-752. [PMID: 32865313 DOI: 10.1002/ajmg.c.31828] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 07/25/2020] [Accepted: 07/28/2020] [Indexed: 12/17/2022]
Abstract
Leber congenital amaurosis (LCA) and early-onset retinal dystrophy (EORD) are severe inherited retinal dystrophy that can cause deep blindness childhood. They represent 5% of all retinal dystrophies in the world population and about 10% in Brazil. Clinical findings and molecular basis of syndromic and nonsyndromic LCA/EORD in a Brazilian sample (152 patients/137 families) were studied. In this population, 15 genes were found to be related to the phenotype, 38 new variants were detected and four new complex alleles were discovered. Among 123 variants found, the most common were CEP290: c.2991+1655A>G, CRB1: p.Cys948Tyr, and RPGRIP1: exon10-18 deletion.
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Affiliation(s)
- Juliana Maria Ferraz Sallum
- Department of Ophthalmology, Universidade Federal de São Paulo, Sao Paulo, Brazil.,Instituto de Genética Ocular, Sao Paulo, Brazil
| | - Fabiana Louise Motta
- Department of Ophthalmology, Universidade Federal de São Paulo, Sao Paulo, Brazil.,Instituto de Genética Ocular, Sao Paulo, Brazil
| | - Gavin Arno
- UCL Institute of Ophthalmology, London, UK.,Moorfields Eye Hospital, London, UK
| | - Fernanda Belga Ottoni Porto
- INRET Clínica e Centro de Pesquisa, Belo Horizonte, Minas Gerais, Brazil.,Centro Oftalmológico de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | - Rubens Belfort
- Department of Ophthalmology, Universidade Federal de São Paulo, Sao Paulo, Brazil
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8
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Cisneros E, di Marco F, Rueda-Carrasco J, Lillo C, Pereyra G, Martín-Bermejo MJ, Vargas A, Sanchez R, Sandonís Á, Esteve P, Bovolenta P. Sfrp1 deficiency makes retinal photoreceptors prone to degeneration. Sci Rep 2020; 10:5115. [PMID: 32198470 PMCID: PMC7083943 DOI: 10.1038/s41598-020-61970-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 03/05/2020] [Indexed: 12/11/2022] Open
Abstract
Millions of individuals worldwide suffer from impaired vision, a condition with multiple origins that often impinge upon the light sensing cells of the retina, the photoreceptors, affecting their integrity. The molecular components contributing to this integrity are however not yet fully understood. Here we have asked whether Secreted Frizzled Related Protein 1 (SFRP1) may be one of such factors. SFRP1 has a context-dependent function as modulator of Wnt signalling or of the proteolytic activity of A Disintegrin And Metalloproteases (ADAM) 10, a main regulator of neural cell-cell communication. We report that in Sfrp1−/− mice, the outer limiting membrane (OLM) is discontinuous and the photoreceptors disorganized and more prone to light-induced damage. Sfrp1 loss significantly enhances the effect of the Rpe65Leu450Leu genetic variant -present in the mouse genetic background- which confers sensitivity to light-induced stress. These alterations worsen with age, affect visual function and are associated to an increased proteolysis of Protocadherin 21 (PCDH21), localized at the photoreceptor outer segment, and N-cadherin, an OLM component. We thus propose that SFRP1 contributes to photoreceptor fitness with a mechanism that involves the maintenance of OLM integrity. These conclusions are discussed in view of the broader implication of SFRP1 in neurodegeneration and aging.
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Affiliation(s)
- Elsa Cisneros
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain.,Departamento de Biología Celular y Patología, Universidad de Salamanca, Instituto de Neurociencias de Castilla y León and IBSAL, Salamanca, Spain.,Centro Universitario Internacional de Madrid (CUNIMAD), Dept. de Biología de Sistemas, Universidad de Alcalá, Madrid, Spain
| | - Fabiana di Marco
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | | | - Concepción Lillo
- Departamento de Biología Celular y Patología, Universidad de Salamanca, Instituto de Neurociencias de Castilla y León and IBSAL, Salamanca, Spain
| | | | | | - Alba Vargas
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - Rocío Sanchez
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain
| | - África Sandonís
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Pilar Esteve
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain.,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain
| | - Paola Bovolenta
- Centro de Biología Molecular Severo Ochoa, CSIC-UAM, Madrid, Spain. .,Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), Madrid, Spain.
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9
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Tait CM, Chinnaiya K, Manning E, Murtaza M, Ashton JP, Furley N, Hill CJ, Alves CH, Wijnholds J, Erdmann KS, Furley A, Rashbass P, Das RM, Storey KG, Placzek M. Crumbs2 mediates ventricular layer remodelling to form the spinal cord central canal. PLoS Biol 2020; 18:e3000470. [PMID: 32150534 PMCID: PMC7108746 DOI: 10.1371/journal.pbio.3000470] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 03/31/2020] [Accepted: 02/18/2020] [Indexed: 11/27/2022] Open
Abstract
In the spinal cord, the central canal forms through a poorly understood process termed dorsal collapse that involves attrition and remodelling of pseudostratified ventricular layer (VL) cells. Here, we use mouse and chick models to show that dorsal ventricular layer (dVL) cells adjacent to dorsal midline Nestin(+) radial glia (dmNes+RG) down-regulate apical polarity proteins, including Crumbs2 (CRB2) and delaminate in a stepwise manner; live imaging shows that as one cell delaminates, the next cell ratchets up, the dmNes+RG endfoot ratchets down, and the process repeats. We show that dmNes+RG secrete a factor that promotes loss of cell polarity and delamination. This activity is mimicked by a secreted variant of Crumbs2 (CRB2S) which is specifically expressed by dmNes+RG. In cultured MDCK cells, CRB2S associates with apical membranes and decreases cell cohesion. Analysis of Crb2F/F/Nestin-Cre+/- mice, and targeted reduction of Crb2/CRB2S in slice cultures reveal essential roles for transmembrane CRB2 (CRB2TM) and CRB2S on VL cells and dmNes+RG, respectively. We propose a model in which a CRB2S-CRB2TM interaction promotes the progressive attrition of the dVL without loss of overall VL integrity. This novel mechanism may operate more widely to promote orderly progenitor delamination.
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Affiliation(s)
- Christine M Tait
- Department of Biomedical Science and Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Kavitha Chinnaiya
- Department of Biomedical Science and Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Elizabeth Manning
- Department of Biomedical Science and Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Mariyam Murtaza
- Department of Biomedical Science and Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - John-Paul Ashton
- Department of Biomedical Science and Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Nicholas Furley
- Department of Biomedical Science and Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Chris J Hill
- Department of Biomedical Science and Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - C Henrique Alves
- Department of Ophthalmology, Leiden University Medical Centre, Leiden, the Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Centre, Leiden, the Netherlands
| | - Kai S Erdmann
- Department of Biomedical Science and Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Andrew Furley
- Department of Biomedical Science and Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Penny Rashbass
- Department of Biomedical Science and Bateson Centre, University of Sheffield, Sheffield, United Kingdom
| | - Raman M Das
- Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Kate G Storey
- Division of Cell and Developmental Biology, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Marysia Placzek
- Department of Biomedical Science and Bateson Centre, University of Sheffield, Sheffield, United Kingdom
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10
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Kraut RS, Knust E. Changes in endolysosomal organization define a pre-degenerative state in the crumbs mutant Drosophila retina. PLoS One 2019; 14:e0220220. [PMID: 31834921 PMCID: PMC6910688 DOI: 10.1371/journal.pone.0220220] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Accepted: 11/24/2019] [Indexed: 01/06/2023] Open
Abstract
Mutations in the epithelial polarity gene crumbs (crb) lead to retinal degeneration in Drosophila and in humans. The overall morphology of the retina and its deterioration in Drosophila crb mutants has been well-characterized, but the cell biological origin of the degeneration is not well understood. Degenerative conditions in the retina and elsewhere in the nervous system often involve defects in degradative intracellular trafficking pathways. So far, however, effects of crb on the endolysosomal system, or on the spatial organization of these compartments in photoreceptor cells have not been described. We therefore asked whether photoreceptors in crb mutants exhibit alterations in endolysosomal compartments under pre-degenerative conditions, where the retina is still morphologically intact. Data presented here show that, already well before the onset of degeneration, Arl8, Rab7, and Atg8-carrying endolysosomal and autophagosomal compartments undergo changes in morphology and positioning with respect to each other in crb mutant retinas. We propose that these changes may be early signs of the degeneration-prone condition in crb retinas.
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Affiliation(s)
- Rachel S. Kraut
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse, Dresden, Germany
- * E-mail:
| | - Elisabeth Knust
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse, Dresden, Germany
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11
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Xu L, Bolch SN, Santiago CP, Dyka FM, Akil O, Lobanova ES, Wang Y, Martemyanov KA, Hauswirth WW, Smith WC, Handa JT, Blackshaw S, Ash JD, Dinculescu A. Clarin-1 expression in adult mouse and human retina highlights a role of Müller glia in Usher syndrome. J Pathol 2019; 250:195-204. [PMID: 31625146 PMCID: PMC7003947 DOI: 10.1002/path.5360] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 09/17/2019] [Accepted: 10/16/2019] [Indexed: 02/06/2023]
Abstract
Usher syndrome type 3 (USH3) is an autosomal recessively inherited disorder caused by mutations in the gene clarin‐1 (CLRN1), leading to combined progressive hearing loss and retinal degeneration. The cellular distribution of CLRN1 in the retina remains uncertain, either because its expression levels are low or because its epitopes are masked. Indeed, in the adult mouse retina, Clrn1 mRNA is developmentally downregulated, detectable only by RT‐PCR. In this study we used the highly sensitive RNAscope in situ hybridization assay and single‐cell RNA‐sequencing techniques to investigate the distribution of Clrn1 and CLRN1 in mouse and human retina, respectively. We found that Clrn1 transcripts in mouse tissue are localized to the inner retina during postnatal development and in adult stages. The pattern of Clrn1 mRNA cellular expression is similar in both mouse and human adult retina, with CLRN1 transcripts being localized in Müller glia, and not photoreceptors. We generated a novel knock‐in mouse with a hemagglutinin (HA) epitope‐tagged CLRN1 and showed that CLRN1 is expressed continuously at the protein level in the retina. Following enzymatic deglycosylation and immunoblotting analysis, we detected a single CLRN1‐specific protein band in homogenates of mouse and human retina, consistent in size with the main CLRN1 isoform. Taken together, our results implicate Müller glia in USH3 pathology, placing this cell type to the center of future mechanistic and therapeutic studies to prevent vision loss in this disease. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Lei Xu
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Susan N Bolch
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Clayton P Santiago
- Solomon H Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD, USA
| | - Frank M Dyka
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Omar Akil
- Department of Otolaryngology-HNS, University of California, San Francisco, CA, USA
| | | | - Yuchen Wang
- Department of Neuroscience, The Scripps Research Institute, Jupiter, FL, USA
| | | | | | - W Clay Smith
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - James T Handa
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Seth Blackshaw
- Solomon H Snyder Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD, USA.,Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Center for Human Systems Biology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, USA.,Kavli Neuroscience Discovery Institute, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - John D Ash
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
| | - Astra Dinculescu
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
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12
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Identification of Genes Required for Apical Protein Trafficking in Drosophila Photoreceptor Cells. G3-GENES GENOMES GENETICS 2019; 9:4007-4017. [PMID: 31649044 PMCID: PMC6893196 DOI: 10.1534/g3.119.400635] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Drosophila melanogaster photoreceptor cells are highly polarized epithelial cells. Their apical membrane is further subdivided into the stalk membrane and the light-sensing rhabdomere. The photo-pigment Rhodopsin1 (Rh1) localizes to the rhabdomere, whereas the apical determinant Crumbs (Crb) is enriched at the stalk membrane. The proteoglycan Eyes shut (Eys) is secreted through the apical membrane into an inter-rhabdomeral space. Rh1, Crb, and Eys are essential for the development of photoreceptor cells, normal vision, and photoreceptor cell survival. Human orthologs of all three proteins have been linked to retinal degenerative diseases. Here, we describe an RNAi-based screen examining the importance of 237 trafficking-related genes in apical trafficking of Eys, Rh1, and Crb. We found 28 genes that have an effect on the localization and/or levels of these apical proteins and analyzed several factors in more detail. We show that the Arf GEF protein Sec71 is required for biosynthetic traffic of both apical and basolateral proteins, that the exocyst complex and the microtubule-based motor proteins dynein and kinesin promote the secretion of Eys and Rh1, and that Syntaxin 7/Avalanche controls the endocytosis of Rh1, Eys, and Crb.
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13
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Quinn PM, Wijnholds J. Retinogenesis of the Human Fetal Retina: An Apical Polarity Perspective. Genes (Basel) 2019; 10:E987. [PMID: 31795518 PMCID: PMC6947654 DOI: 10.3390/genes10120987] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 12/20/2022] Open
Abstract
The Crumbs complex has prominent roles in the control of apical cell polarity, in the coupling of cell density sensing to downstream cell signaling pathways, and in regulating junctional structures and cell adhesion. The Crumbs complex acts as a conductor orchestrating multiple downstream signaling pathways in epithelial and neuronal tissue development. These pathways lead to the regulation of cell size, cell fate, cell self-renewal, proliferation, differentiation, migration, mitosis, and apoptosis. In retinogenesis, these are all pivotal processes with important roles for the Crumbs complex to maintain proper spatiotemporal cell processes. Loss of Crumbs function in the retina results in loss of the stratified appearance resulting in retinal degeneration and loss of visual function. In this review, we begin by discussing the physiology of vision. We continue by outlining the processes of retinogenesis and how well this is recapitulated between the human fetal retina and human embryonic stem cell (ESC) or induced pluripotent stem cell (iPSC)-derived retinal organoids. Additionally, we discuss the functionality of in utero and preterm human fetal retina and the current level of functionality as detected in human stem cell-derived organoids. We discuss the roles of apical-basal cell polarity in retinogenesis with a focus on Leber congenital amaurosis which leads to blindness shortly after birth. Finally, we discuss Crumbs homolog (CRB)-based gene augmentation.
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Affiliation(s)
- Peter M.J. Quinn
- Department of Ophthalmology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands;
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center, 2300 RC Leiden, The Netherlands;
- The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, 1105 BA Amsterdam, The Netherlands
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14
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Lattner J, Leng W, Knust E, Brankatschk M, Flores-Benitez D. Crumbs organizes the transport machinery by regulating apical levels of PI(4,5)P 2 in Drosophila. eLife 2019; 8:e50900. [PMID: 31697234 PMCID: PMC6881148 DOI: 10.7554/elife.50900] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 10/25/2019] [Indexed: 12/12/2022] Open
Abstract
An efficient vectorial intracellular transport machinery depends on a well-established apico-basal polarity and is a prerequisite for the function of secretory epithelia. Despite extensive knowledge on individual trafficking pathways, little is known about the mechanisms coordinating their temporal and spatial regulation. Here, we report that the polarity protein Crumbs is essential for apical plasma membrane phospholipid-homeostasis and efficient apical secretion. Through recruiting βHeavy-Spectrin and MyosinV to the apical membrane, Crumbs maintains the Rab6-, Rab11- and Rab30-dependent trafficking and regulates the lipid phosphatases Pten and Ocrl. Crumbs knock-down results in increased apical levels of PI(4,5)P2 and formation of a novel, Moesin- and PI(4,5)P2-enriched apical membrane sac containing microvilli-like structures. Our results identify Crumbs as an essential hub required to maintain the organization of the apical membrane and the physiological activity of the larval salivary gland.
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Affiliation(s)
- Johanna Lattner
- Max-Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG)DresdenGermany
| | - Weihua Leng
- Max-Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG)DresdenGermany
| | - Elisabeth Knust
- Max-Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG)DresdenGermany
| | - Marko Brankatschk
- The Biotechnological Center of the TU Dresden (BIOTEC)DresdenGermany
| | - David Flores-Benitez
- Max-Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG)DresdenGermany
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15
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Ahmed Khan S, Richard Nestel A. CRB1 Gene Mutation Causing Different Phenotypes of Leber Congenital Amaurosis in Siblings. J Ophthalmic Vis Res 2019; 14:518-524. [PMID: 31875109 PMCID: PMC6825708 DOI: 10.18502/jovr.v14i4.5467] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 02/10/2019] [Indexed: 12/19/2022] Open
Abstract
Purpose We report a rare case of CRB1gene mutation in two siblings (sisters) affected with the exact same genetic mutation on both CRB1genes resulting in varying phenotypes. Case Report CRB1gene mutation in this case has resulted in causing varying degrees of Leber congenital amaurosis (LCA) in both sisters with a more severe phenotype in the older sibling causing LCA-8 with retinitis pigmentosa spectrum in both eyes and a milder phenotype causing LCA-8 with less severe rod cone dystrophy in the younger sister. Conclusion In summary, the mechanisms of varying phenotypes resulting from CRB1 genetic mutation are still not well understood. We concluded that the presence of different phenotypes associated with identical genotypic mutation of a single gene in siblings or in a family is important especially when dealing with retinal dystrophies.
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16
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Cytoglobin deficiency potentiates Crb1-mediated retinal degeneration in rd8 mice. Dev Biol 2019; 458:141-152. [PMID: 31634437 DOI: 10.1016/j.ydbio.2019.10.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 10/15/2019] [Accepted: 10/16/2019] [Indexed: 02/02/2023]
Abstract
PURPOSE The purpose of this study is to determine the effect of Cytoglobin (Cygb) deficiency on Crb1-related retinopathy. The Crb1 cell polarity complex is required for photoreceptor function and survival. Crb1-related retinopathies encompass a broad range of phenotypes which are not completely explained by the variability of Crb1 mutations. Genes thought to modify Crb1 function are therefore important targets of research. The biological function of Cygb involves oxygen delivery, scavenging of reactive oxygen species, and nitric oxide metabolism. However, the relationship of Cygb to diseases involving the Crb1 cell polarity complex is unknown. METHODS Cygb knockout mice homozygous for the rd8 mutation (Cygb-/-rd8/rd8) were screened for ocular abnormalities and imaged using optical coherence tomography and fundus photography. Electroretinography was performed, as was histology and immunohistochemistry. Quantitative PCR was used to determine the effect of Cygb deficiency on transcription of Crb1 related cell polarity genes. RESULTS Cygb-/-rd8/rd8 mice develop an abnormal retina with severe lamination abnormalities. The retina undergoes progressive degeneration with the ventral retina more severely affected than the dorsal retina. Cygb expression is in neurons of the retinal ganglion cell layer and inner nuclear layer. Immunohistochemical studies suggest that cell death predominates in the photoreceptors. Electroretinography amplitudes show reduced a- and b-waves, consistent with photoreceptor disease. Cygb deficient retinas had only modest transcriptional perturbations of Crb1-related cell polarity genes. Cygb-/- mice without the rd8 mutation did not exhibit obvious retinal abnormalities. CONCLUSIONS Cygb is necessary for retinal lamination, maintenance of cell polarity, and photoreceptor survival in rd8 mice. These results are consistent with Cygb as a disease modifying gene in Crb1-related retinopathy. Further studies are necessary to investigate the role of Cygb in the human retina.
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17
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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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18
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Identification of CRB1 mutations in two Chinese consanguineous families exhibiting autosomal recessive retinitis pigmentosa. Mol Med Rep 2019; 20:2922-2928. [PMID: 31322236 DOI: 10.3892/mmr.2019.10495] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 06/12/2019] [Indexed: 11/05/2022] Open
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19
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Quinn PM, Mulder AA, Henrique Alves C, Desrosiers M, de Vries SI, Klooster J, Dalkara D, Koster AJ, Jost CR, Wijnholds J. Loss of CRB2 in Müller glial cells modifies a CRB1-associated retinitis pigmentosa phenotype into a Leber congenital amaurosis phenotype. Hum Mol Genet 2019; 28:105-123. [PMID: 30239717 DOI: 10.1093/hmg/ddy337] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Accepted: 09/17/2018] [Indexed: 11/14/2022] Open
Abstract
Variations in the human Crumbs homolog-1 (CRB1) gene lead to an array of retinal dystrophies including early onset of retinitis pigmentosa (RP) and Leber congenital amaurosis (LCA) in children. To investigate the physiological roles of CRB1 and CRB2 in retinal Müller glial cells (MGCs), we analysed mouse retinas lacking both proteins in MGC. The peripheral retina showed a faster progression of dystrophy than the central retina. The central retina showed retinal folds, disruptions at the outer limiting membrane, protrusion of photoreceptor nuclei into the inner and outer segment layers and ingression of photoreceptor nuclei into the photoreceptor synaptic layer. The peripheral retina showed a complete loss of the photoreceptor synapse layer, intermingling of photoreceptor nuclei within the inner nuclear layer and ectopic photoreceptor cells in the ganglion cell layer. Electroretinography showed severe attenuation of the scotopic a-wave at 1 month of age with responses below detection levels at 3 months of age. The double knockout mouse retinas mimicked a phenotype equivalent to a clinical LCA phenotype due to loss of CRB1. Localization of CRB1 and CRB2 in non-human primate (NHP) retinas was analyzed at the ultrastructural level. We found that NHP CRB1 and CRB2 proteins localized to the subapical region adjacent to adherens junctions at the outer limiting membrane in MGC and photoreceptors. Our data suggest that loss of CRB2 in MGC aggravates the CRB1-associated RP-like phenotype towards an LCA-like phenotype.
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Affiliation(s)
- Peter M Quinn
- Department of Ophthalmology, Leiden University Medical Center, RC Leiden, The Netherlands
| | - Aat A Mulder
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), RC Leiden, The Netherlands
| | - C Henrique Alves
- Department of Ophthalmology, Leiden University Medical Center, RC Leiden, The Netherlands
| | - Mélissa Desrosiers
- Department of Therapeutics, Institut de la Vision, Sorbonne Universités, UPMC Univ Paris, UMR_S INSERM, CNRS, UMR, Paris, France
| | - Sharon I de Vries
- Department of Axonal Signaling, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), BA Amsterdam, The Netherlands
| | - Jan Klooster
- Department of Retina Signal Processing, Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), BA Amsterdam, The Netherlands
| | - Deniz Dalkara
- Department of Therapeutics, Institut de la Vision, Sorbonne Universités, UPMC Univ Paris, UMR_S INSERM, CNRS, UMR, Paris, France
| | - Abraham J Koster
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), RC Leiden, The Netherlands
| | - Carolina R Jost
- Department of Cell & Chemical Biology, Leiden University Medical Center (LUMC), RC Leiden, The Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center, RC Leiden, The Netherlands.,The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, BA Amsterdam, The Netherlands
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20
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Hartenstein V, Yuan M, Younossi-Hartenstein A, Karandikar A, Bernardo-Garcia FJ, Sprecher S, Knust E. Serial electron microscopic reconstruction of the drosophila larval eye: Photoreceptors with a rudimentary rhabdomere of microvillar-like processes. Dev Biol 2019; 453:56-67. [PMID: 31158364 DOI: 10.1016/j.ydbio.2019.05.017] [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: 03/18/2019] [Revised: 05/30/2019] [Accepted: 05/31/2019] [Indexed: 11/26/2022]
Abstract
Photoreceptor cells (PRCs) across the animal kingdom are characterized by a stacking of apical membranes to accommodate the high abundance of photopigment. In arthropods and many other invertebrate phyla PRC membrane stacks adopt the shape of densely packed microvilli that form a structure called rhabdomere. PRCs and surrounding accessory cells, including pigment cells and lens-forming cells, are grouped in stereotyped units, the ommatidia. In larvae of holometabolan insects, eyes (called stemmata) are reduced in terms of number and composition of ommatidia. The stemma of Drosophila (Bolwig organ) is reduced to a bilateral cluster of subepidermal PRCs, lacking all other cell types. In the present paper we have analyzed the development and fine structure of the Drosophila larval PRCs. Shortly after their appearance in the embryonic head ectoderm, PRC precursors delaminate and lose expression of apical markers of epithelial cells, including Crumbs and several centrosome-associated proteins. In the early first instar larva, PRCs show an expanded, irregularly shaped apical surface that is folded into multiple horizontal microvillar-like processes (MLPs). Apical PRC membranes and MLPs are covered with a layer of extracellular matrix. MLPs are predominantly aligned along an axis that extends ventro-anteriorly to dorso-posteriorly, but vary in length, diameter, and spacing. Individual MLPs present a "beaded" shape, with thick segments (0.2-0.3 μm diameter) alternating with thin segments (>0.1 μm). We show that loss of the glycoprotein Chaoptin, which is absolutely essential for rhabdomere formation in the adult PRCs, does not lead to severe abnormalities in larval PRCs.
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Affiliation(s)
- Volker Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA.
| | - Michaela Yuan
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307, Dresden, Germany
| | - Amelia Younossi-Hartenstein
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | - Aanavi Karandikar
- Department of Molecular Cell and Developmental Biology, University of California Los Angeles, Los Angeles, CA, 90095, USA
| | | | - Simon Sprecher
- Department of Biology, University of Fribourg, 10, Ch. du Musée, 1700, Fribourg, Switzerland
| | - Elisabeth Knust
- Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307, Dresden, Germany
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21
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Quinn PM, Alves CH, Klooster J, Wijnholds J. CRB2 in immature photoreceptors determines the superior-inferior symmetry of the developing retina to maintain retinal structure and function. Hum Mol Genet 2019; 27:3137-3153. [PMID: 29893966 DOI: 10.1093/hmg/ddy194] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 05/11/2018] [Indexed: 11/13/2022] Open
Abstract
The mammalian apical-basal determinant Crumbs homolog-1 (CRB1) plays a crucial role in retinal structure and function by the maintenance of adherens junctions between photoreceptors and Müller glial cells. Patients with mutations in the CRB1 gene develop retinal dystrophies, including early-onset retinitis pigmentosa and Leber congenital amaurosis. Previously, we showed that Crb1 knockout mice developed a slow-progressing retinal phenotype at foci in the inferior retina, although specific ablation of Crb2 in immature photoreceptors leads to an early-onset phenotype throughout the retina. Here, we conditionally disrupted one or both alleles of Crb2 in immature photoreceptors, on a genetic background lacking Crb1, and studied the retinal dystrophies thereof. Our data showed that disruption of one allele of Crb2 in immature photoreceptors caused a substantial aggravation of the Crb1 phenotype in the entire inferior retina. The photoreceptor layer showed early-onset progressive thinning limited to the inferior retina, although the superior retina maintained intact. Surprisingly, disruption of both alleles of Crb2 in immature photoreceptors further aggravated the phenotype. Throughout the retina, photoreceptor synapses were disrupted and photoreceptor nuclei intermingled with nuclei of the inner nuclear layer. In the superior retina, the ganglion cell layer appeared thicker because of ectopic nuclei of photoreceptors. In conclusion, the data suggest that CRB2 is required to maintain retinal progenitor and photoreceptor cell adhesion and prevent photoreceptor ingression into the immature inner retina. We hypothesize, from these animal models, that decreased levels of CRB2 in immature photoreceptors adjust retinitis pigmentosa because of the loss of CRB1 into Leber congenital amaurosis phenotype.
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Affiliation(s)
- Peter M Quinn
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - C Henrique Alves
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands
| | - Jan Klooster
- Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center, Leiden, The Netherlands.,Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences, Amsterdam, The Netherlands
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22
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Moore BA, Roux MJ, Sebbag L, Cooper A, Edwards SG, Leonard BC, Imai DM, Griffey S, Bower L, Clary D, Lloyd KCK, Hérault Y, Thomasy SM, Murphy CJ, Moshiri A. A Population Study of Common Ocular Abnormalities in C57BL/6N rd8 Mice. Invest Ophthalmol Vis Sci 2019; 59:2252-2261. [PMID: 29847629 PMCID: PMC5935295 DOI: 10.1167/iovs.17-23513] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Purpose The purpose of this study was to quantify the frequency and severity of ocular abnormalities affecting wild-type C57BL/6N mice, the most common strain used worldwide for the creation of single-gene knockouts. Methods A total of 2773 animals (5546 eyes) were examined at one colony at UC Davis and in three more colonies at the Institut Clinique de la Souris in Strasbourg, France. Mice were examined at 15 to 16 weeks postnatal age by performing anterior segment biomicroscopy, posterior segment examination by indirect ophthalmoscopy, intraocular pressure measurement, and optical coherence tomography of anterior and posterior segment structures. Results Common ocular findings in the C57BL/6N strain included corneal deposits (3%), increased optical density of the anterior lens capsule (67%), punctate nuclear cataracts (98%), vitreous crystalline deposits (61%), hyaloid vascular remnant (6%), and retinal dysplasia attributed to the rd8 mutation (58%). Interestingly, retinal dysplasia was more common in male mice in all four breeding colonies evaluated in this study. The thickness of ocular tissues and compartments were measured by spectral-domain optical coherence tomography, including the central cornea, anterior chamber, vitreous, and retinal layers. Intraocular pressure was measured by rebound tonometry. Conclusions Ocular abnormalities are common in anterior and posterior segments of the C57BL/6N mouse, the most common background on which single-gene knockout mice have been made. It is important that vision scientists understand the extent and variability of ocular findings associated with this particular genetic background of mice.
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Affiliation(s)
- Bret A Moore
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Michel J Roux
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France
| | - Lionel Sebbag
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Ann Cooper
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Sydney G Edwards
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Brian C Leonard
- William R. Pritchard Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California-Davis, Davis, California, United States
| | - Denise M Imai
- Comparative Pathology Laboratory, School of Veterinary Medicine, UC Davis, Davis, California, United States
| | - Stephen Griffey
- Comparative Pathology Laboratory, School of Veterinary Medicine, UC Davis, Davis, California, United States
| | - Lynette Bower
- Mouse Biology Program, University of California-Davis, Davis, California, United States
| | - Dave Clary
- Mouse Biology Program, University of California-Davis, Davis, California, United States
| | - K C Kent Lloyd
- Mouse Biology Program, University of California-Davis, Davis, California, United States.,Department of Surgery, School of Medicine, University of California-Davis, Sacramento, California, United States
| | - Yann Hérault
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Université de Strasbourg, Illkirch, France.,Centre National de la Recherche Scientifique, UMR7104, Illkirch, France.,Institut National de la Santé et de la Recherche Médicale, U964, Illkirch, France.,Université de Strasbourg, Illkirch, France.,CELPHEDIA, PHENOMIN, Institut Clinique de la Souris (ICS), CNRS, INSERM, Université de Strasbourg, Illkirch, France
| | - Sara M Thomasy
- Department of Veterinary Surgical and Radiological Sciences, School of Veterinary Medicine, UC Davis, Davis, California, United States.,Department of Ophthalmology & Vision Science, School of Medicine, University of California-Davis, Sacramento, California, United States
| | - Christopher J Murphy
- Department of Veterinary Surgical and Radiological Sciences, School of Veterinary Medicine, UC Davis, Davis, California, United States.,Department of Ophthalmology & Vision Science, School of Medicine, University of California-Davis, Sacramento, California, United States
| | - Ala Moshiri
- Department of Ophthalmology & Vision Science, School of Medicine, University of California-Davis, Sacramento, California, United States
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23
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Chen X, Jiang C, Yang D, Sun R, Wang M, Sun H, Xu M, Zhou L, Chen M, Xie P, Yan B, Liu Q, Zhao C. CRB2 mutation causes autosomal recessive retinitis pigmentosa. Exp Eye Res 2018; 180:164-173. [PMID: 30593785 DOI: 10.1016/j.exer.2018.12.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 12/21/2018] [Accepted: 12/21/2018] [Indexed: 01/29/2023]
Abstract
Retinitis pigmentosa (RP), the most common form of inherited retinal dystrophies, exhibits significant genetic heterogeneity. The crumbs homolog 2 (CRB2) protein, together with CRB1 and CRB3, belongs to the Crumbs family. Given that CRB1 mutations account for 4% of RP cases, the role of CRB2 mutations in RP etiology has long been hypothesized but never confirmed. Herein, we report the identification of CRB2 as a novel RP causative gene in a Chinese consanguineous family and have analyzed its pathogenic effects. Comprehensive ophthalmic and systemic evaluations confirmed the clinical diagnosis of the two patients in this family as RP. WES revealed a homozygous missense mutation, CRB2 p.R1249G, to segregate the RP phenotype, which was highly conserved among multiple species. In vitro cellular study revealed that this mutation not only interrupted the stability of the transcribed CRB2 mRNA and the encoded CRB2 protein, but also interfered with the wild type CRB2 mRNA/protein and decreased their expression. This mutation was also shown to trigger epithelial-mesenchymal transition (EMT) in retinal pigment epithelium (RPE) cells, thus impairing regular RPE phagocytosis and induce RPE degeneration and apoptosis. Thus, we conclude that CRB2 p.R1249G mutation causes RP via accelerating EMT, dysfunction and loss of RPE cells, and establish CRB2 as a novel Crumbs family member associated with non-syndromic RP. We provide important hints for understanding of CRB2 defects and retinopathy, and for the involvement of EMT of RPE cells in RP pathogenesis.
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Affiliation(s)
- Xue Chen
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200023, China; Key Laboratory of Myopia of State Health Ministry (Fudan University) and Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200023, China
| | - Chao Jiang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Daidi Yang
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Ruxu Sun
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Min Wang
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200023, China; Key Laboratory of Myopia of State Health Ministry (Fudan University) and Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200023, China
| | - Hong Sun
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Min Xu
- Department of Ophthalmology, Northern Jiangsu People's Hospital, Yangzhou, 211406, China
| | - Luyin Zhou
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Mingkang Chen
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Ping Xie
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China
| | - Biao Yan
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200023, China; Key Laboratory of Myopia of State Health Ministry (Fudan University) and Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200023, China
| | - Qinghuai Liu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China.
| | - Chen Zhao
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China; Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200023, China; Key Laboratory of Myopia of State Health Ministry (Fudan University) and Shanghai Key Laboratory of Visual Impairment and Restoration, Shanghai, 200023, China.
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24
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Dolón JF, Paniagua AE, Valle V, Segurado A, Arévalo R, Velasco A, Lillo C. Expression and localization of the polarity protein CRB2 in adult mouse brain: a comparison with the CRB1 rd8 mutant mouse model. Sci Rep 2018; 8:11652. [PMID: 30076417 PMCID: PMC6076319 DOI: 10.1038/s41598-018-30210-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Accepted: 07/24/2018] [Indexed: 11/09/2022] Open
Abstract
Acquisition of cell polarization is essential for the performance of crucial functions, like a successful secretion and appropriate cell signaling in many tissues, and it depends on the correct functioning of polarity proteins, including the Crumbs complex. The CRB proteins, CRB1, CRB2 and CRB3, identified in mammals, are expressed in epithelial-derived tissues like brain, kidney and retina. CRB2 has a ubiquitous expression and has been detected in embryonic brain tissue; but currently there is no data regarding its localization in the adult brain. In our study, we characterized the presence of CRB2 in adult mice brain, where it is particularly enriched in cortex, hippocampus, hypothalamus and cerebellum. Double immunofluorescence analysis confirmed that CRB2 is a neuron-specific protein, present in both soma and projections where colocalizes with certain populations of exocytic and endocytic vesicles and with other members of the Crumbs complex. Finally, in the cortex of CRB1rd8 mutant mice that contain a mutation in the Crb1 gene generating a truncated CRB1 protein, there is an abnormal increase in the expression levels of the CRB2 protein which suggests a possible compensatory mechanism for the malfunction of CRB1 in this mutant background.
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Affiliation(s)
- Jorge F Dolón
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Antonio E Paniagua
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain.,Department of Ophthalmology and Stein Eye Institute, University of California, Los Angeles, CA, 90095, USA
| | - Vicente Valle
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Alicia Segurado
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Rosario Arévalo
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Almudena Velasco
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Concepción Lillo
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain.
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25
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Pichaud F. PAR-Complex and Crumbs Function During Photoreceptor Morphogenesis and Retinal Degeneration. Front Cell Neurosci 2018; 12:90. [PMID: 29651238 PMCID: PMC5884931 DOI: 10.3389/fncel.2018.00090] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 03/15/2018] [Indexed: 12/30/2022] Open
Abstract
The fly photoreceptor has long been used as a model to study sensory neuron morphogenesis and retinal degeneration. In particular, elucidating how these cells are built continues to help further our understanding of the mechanisms of polarized cell morphogenesis, intracellular trafficking and the causes of human retinal pathologies. The conserved PAR complex, which in flies consists of Cdc42-PAR6-aPKC-Bazooka, and the transmembrane protein Crumbs (Crb) are key players during photoreceptor morphogenesis. While the PAR complex regulates polarity in many cell types, Crb function in polarity is relatively specific to epithelial cells. Together Cdc42-PAR6-aPKC-Bazooka and Crb orchestrate the differentiation of the photoreceptor apical membrane (AM) and zonula adherens (ZA), thus allowing these cells to assemble into a neuro-epithelial lattice. In addition to its function in epithelial polarity, Crb has also been shown to protect fly photoreceptors from light-induced degeneration, a process linked to Rhodopsin expression and trafficking. Remarkably, mutations in the human Crumbs1 (CRB1) gene lead to retinal degeneration, making the fly photoreceptor a powerful disease model system.
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Affiliation(s)
- Franck Pichaud
- Medical Research Council, Laboratory for Molecular Cell Biology, University College London, London, United Kingdom
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26
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Fu J, Nagashima M, Guo C, Raymond PA, Wei X. Novel Animal Model of Crumbs-Dependent Progressive Retinal Degeneration That Targets Specific Cone Subtypes. Invest Ophthalmol Vis Sci 2018; 59:505-518. [PMID: 29368007 PMCID: PMC5786287 DOI: 10.1167/iovs.17-22572] [Citation(s) in RCA: 8] [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: 07/07/2017] [Accepted: 12/10/2017] [Indexed: 01/01/2023] Open
Abstract
Purpose Human Crb1 is implicated in some forms of retinal degeneration, suggesting a role in photoreceptor maintenance. Multiple Crumbs (Crb) polarity genes are expressed in vertebrate retina, although their functional roles are not well understood. To gain further insight into Crb and photoreceptor maintenance, we compared retinal cell densities between wild-type and Tg(RH2-2:Crb2b-sfEX/RH2-2:GFP)pt108b transgenic zebrafish, in which the extracellular domain of Crb2b-short form (Crb2b-sfEX) is expressed in the retina as a secreted protein, which disrupts the planar organization of RGB cones (red, green, and blue) by interfering with Crb2a/2b-based cone-cone adhesion. Methods We used standard morphometric techniques to assess age-related changes in retinal cell densities in adult zebrafish (3 to 27 months old), and to assess effects of the Crb2b-sfEX transgene on retinal structure and photoreceptor densities. Linear cell densities were measured in all retinal layers in radial sections with JB4-Feulgen histology. Planar (surface) densities of cones were determined in retinal flat-mounts. Cell counts from wild-type and pt108b transgenic fish were compared with both a "photoreceptor maintenance index" and statistical analysis of cell counts. Results Age-related changes in retinal cell linear densities and cone photoreceptor planar densities in wild-type adult zebrafish provided a baseline for analysis. Expression of Crb2b-sfEX caused progressive and selective degeneration of RGB cones, but had no effect on ultraviolet-sensitive (UV) cones, and increased numbers of rod photoreceptors. Conclusions These differential responses of RGB cones, UV cones, and rods to sustained exposure to Crb2b-sfEX suggest that Crb-based photoreceptor maintenance mechanisms are highly selective.
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Affiliation(s)
- Jinling Fu
- Department of Ophthalmology, the Second Hospital of Jilin University, Changchun, Jilin, China
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Mikiko Nagashima
- Department of Molecular, Cellular, and Developmental Biology, College of Literature, Science, and the Arts, University of Michigan, Ann Arbor, Michigan, United States
| | - Chuanyu Guo
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
| | - Pamela A. Raymond
- Department of Molecular, Cellular, and Developmental Biology, College of Literature, Science, and the Arts, University of Michigan, Ann Arbor, Michigan, United States
| | - Xiangyun Wei
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, United States
- Department of Developmental Biology, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, United States
- Department of Microbiology and Molecular Genetics, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, United States
- Louis J. Fox Center for Vision Restoration, University of Pittsburgh, School of Medicine, Pittsburgh, Pennsylvania, United States
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27
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Quinn PM, Buck TM, Ohonin C, Mikkers HMM, Wijnholds J. Production of iPS-Derived Human Retinal Organoids for Use in Transgene Expression Assays. Methods Mol Biol 2018; 1715:261-273. [PMID: 29188520 DOI: 10.1007/978-1-4939-7522-8_19] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
In vitro retinal organoid modeling from human pluripotent stem cells is becoming more common place in many ophthalmic laboratories worldwide. These organoids mimic human retinogenesis through formation of organized layered retinal structures that display markers for typical retinal cell types. Pivotally these humanized retinal models provide a stepping stone to the clinic as therapeutic tools and are expected to provide a promising alternative to current animal models. Thus pluripotent stem cell based healthy as well as diseased human retinal organoids are attractive for use in drug potency assays and gene augmentation therapeutics. Here we outline an established protocol for generation of these retinal organoids and how they can be used in conjunction with adeno-associated virus vectors for transgene expression assays.
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Affiliation(s)
- Peter M Quinn
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Thilo M Buck
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Charlotte Ohonin
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Harald M M Mikkers
- Department of Molecular Cell Biology, Leiden University Medical Center (LUMC), Leiden, The Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center (LUMC), Leiden, The Netherlands. .,Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Amsterdam, The Netherlands.
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28
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Kong Y, Naggert JK, Nishina PM. The Impact of Adherens and Tight Junctions on Physiological Function and Pathological Changes in the Retina. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2018; 1074:545-551. [DOI: 10.1007/978-3-319-75402-4_66] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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29
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Peyer SM, Heath-Heckman EAC, McFall-Ngai MJ. Characterization of the cell polarity gene crumbs during the early development and maintenance of the squid-vibrio light organ symbiosis. Dev Genes Evol 2017; 227:375-387. [PMID: 28105525 PMCID: PMC5519459 DOI: 10.1007/s00427-017-0576-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Accepted: 01/13/2017] [Indexed: 11/26/2022]
Abstract
The protein Crumbs is a determinant of apical-basal cell polarity and plays a role in apoptosis of epithelial cells and their protection against photodamage. Using the squid-vibrio system, a model for development of symbiotic partnerships, we examined the modulation of the crumbs gene in host epithelial tissues during initiation and maintenance of the association. The extracellular luminous symbiont Vibrio fischeri colonizes the apical surfaces of polarized epithelia in deep crypts of the Euprymna scolopes light organ. During initial colonization each generation, symbiont harvesting is potentiated by the biochemical and biophysical activity of superficial ciliated epithelia, which are several cell layers from the crypt epithelia where the symbionts reside. Within hours of crypt colonization, the symbionts induce the cell death mediated regression of the remote superficial ciliated fields. However, the crypt cells directly interacting with the symbiont are protected from death. In the squid host, we characterized the gene and encoded protein during light organ morphogenesis and in response to symbiosis. Features of the protein sequence and structure, phylogenetic relationships, and localization patterns in the eye supported assignment of the squid protein to the Crumbs family. In situ hybridization revealed that the crumbs transcript shows opposite expression at the onset of symbiosis in the two different regions of the light organ: elevated levels in the superficial epithelia were attenuated whereas low levels in the crypt epithelia were turned up. Although a rhythmic association in which the host controls the symbiont population over the day-night cycle begins in the juvenile upon colonization, cycling of crumbs was evident only in the adult organ with peak expression coincident with maximum symbiont population and luminescence. Our results provide evidence that crumbs responds to symbiont cues that induce developmental apoptosis and to symbiont population dynamics correlating with luminescence-based stress throughout the duration of the host-microbe association.
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Affiliation(s)
- Suzanne M Peyer
- School of Medicine and Public Health, Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI, 53706, USA.
- McPherson Eye Research Institute, University of Wisconsin, Madison, WI, 53706, USA.
| | - Elizabeth A C Heath-Heckman
- School of Medicine and Public Health, Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI, 53706, USA
- Department of Molecular and Cell Biology, University of California-Berkeley, Berkeley, CA, 94720, USA
| | - Margaret J McFall-Ngai
- School of Medicine and Public Health, Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI, 53706, USA.
- McPherson Eye Research Institute, University of Wisconsin, Madison, WI, 53706, USA.
- Pacific Biosciences Research Center, University of Hawaii at Manoa, Honolulu, HI, 96822, USA.
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30
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Motta FL, Salles MV, Costa KA, Filippelli-Silva R, Martin RP, Sallum JMF. The correlation between CRB1 variants and the clinical severity of Brazilian patients with different inherited retinal dystrophy phenotypes. Sci Rep 2017; 7:8654. [PMID: 28819299 PMCID: PMC5561187 DOI: 10.1038/s41598-017-09035-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 07/20/2017] [Indexed: 12/18/2022] Open
Abstract
Inherited retinal dystrophies are characterized by progressive retina degeneration and mutations in at least 250 genes have been associated as disease-causing. CRB1 is one of many genes analyzed in molecular diagnosis for inherited retinal dystrophy. Crumbs homolog-1 protein encoded by CRB1 is important for cell-to-cell contact, polarization of epithelial cells and the morphogenesis of photoreceptors. Pathogenic variants in CRB1 lead to a huge variety of phenotypes ranging from milder forms of inherited retinal dystrophy, such as retinitis pigmentosa to more severe phenotypes such as Leber congenital amaurosis. In this study, seven novel likely-pathogenic variants were identified: four missense variants (p.Leu479Pro, p.Ala921Pro, p.Cys948Arg and p.Asp1031Asn), two frameshift deletions (c.2536_2542del7 and c.3460_3461delTG) and one frameshift indel variant (c.276_294delinsTGAACACTGTAC). Furthermore, two patients with cone-rod dystrophy due to mutations in CRB1 were reported, supporting previous data, in which mutations in CRB1 can also cause cone-rod dystrophy. Finally, our data suggested there was a direct relation between phenotype severity and the mutation effect on protein functionality in 15 Brazilian CRB1 patients.
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Affiliation(s)
| | | | | | | | - Renan Paulo Martin
- Department of Biophysics, Federal University of Sao Paulo, Sao Paulo, Brazil
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31
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Ghofrani M, Yahyaei M, Brunner HG, Cremers FP, Movasat M, Imran Khan M, Keramatipour M. Homozygosity Mapping and Targeted Sanger Sequencing Identifies Three Novel CRB1 (Crumbs homologue 1) Mutations in Iranian Retinal Degeneration Families. IRANIAN BIOMEDICAL JOURNAL 2017; 21:294-302. [PMID: 28460491 PMCID: PMC5548961 DOI: 10.18869/acadpub.ibj.21.5.294] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Background: Inherited retinal diseases (IRDs) are a group of genetic disorders with high degrees of clinical, genetic and allelic heterogeneity. IRDs generally show progressive retinal cell death resulting in gradual vision loss. IRDs constitute a broad spectrum of disorders including retinitis pigmentosa and Leber congenital amaurosis. In this study, we performed genotyping studies to identify the underlying mutations in three Iranian families. Methods: Having employed homozygosity mapping and Sanger sequencing, we identified the underlying mutations in the crumbs homologue 1 gene. The CRB1 protein is a part of a macromolecular complex with a vital role in retinal cell polarity, morphogenesis, and maintenance. Results: We identified a novel homozygous variant (c.1053_1061del; p.Gly352_Cys354del) in one family, a combination of a novel (c.2086T>C; p.Cys696Arg) and a known variant (c.2234C>T, p.Thr745Met) in another family and a homozygous novel variant (c.3090T>A; p.Asn1030Lys) in a third family. Conclusion: This study shows that mutations in CRB1 are relatively common in Iranian non-syndromic IRD patients.
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Affiliation(s)
- Mohammad Ghofrani
- Department of Medical Genetics, Tehran University of Medical Sciences, Tehran, Iran.,Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Mahin Yahyaei
- Department of Medical Genetics, Tehran University of Medical Sciences, Tehran, Iran
| | - Han G. Brunner
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Frans P.M. Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Morteza Movasat
- Eye Research Center, Tehran University of Medical Sciences, Farabi Eye Hospital, Tehran, Iran
| | - Muhammad Imran Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands
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Quinn PM, Pellissier LP, Wijnholds J. The CRB1 Complex: Following the Trail of Crumbs to a Feasible Gene Therapy Strategy. Front Neurosci 2017; 11:175. [PMID: 28424578 PMCID: PMC5380682 DOI: 10.3389/fnins.2017.00175] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/16/2017] [Indexed: 12/24/2022] Open
Abstract
Once considered science fiction, gene therapy is rapidly becoming scientific reality, targeting a growing number of the approximately 250 genes linked to hereditary retinal disorders such as retinitis pigmentosa and Leber's congenital amaurosis. Powerful new technologies have emerged, leading to the development of humanized models for testing and screening these therapies, bringing us closer to the goal of personalized medicine. These tools include the ability to differentiate human induced pluripotent stem cells (iPSCs) to create a “retina-in-a-dish” model and the self-formed ectodermal autonomous multi-zone, which can mimic whole eye development. In addition, highly specific gene-editing tools are now available, including the CRISPR/Cas9 system and the recently developed homology-independent targeted integration approach, which allows gene editing in non-dividing cells. Variants in the CRB1 gene have long been associated with retinopathies, and more recently the CRB2 gene has also been shown to have possible clinical relevance with respect to retinopathies. In this review, we discuss the role of the CRB protein complex in patients with retinopathy. In addition, we discuss new opportunities provided by stem cells and gene-editing tools, and we provide insight into how the retinal therapeutic pipeline can be improved. Finally, we discuss the current state of adeno-associated virus-mediated gene therapy and how it can be applied to treat retinopathies associated with mutations in CRB1.
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Affiliation(s)
- Peter M Quinn
- Department of Ophthalmology, Leiden University Medical CenterLeiden, Netherlands
| | - Lucie P Pellissier
- Unité Physiologie de la Reproduction et des Comportements, INRA UMR85, Centre National de la Recherche Scientifique UMR-7247, Institut Français du Cheval et de l'Équitation, Université François RabelaisNouzilly, France
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical CenterLeiden, Netherlands.,Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and SciencesAmsterdam, Netherlands
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Tilston-Lünel AM, Haley KE, Schlecht NF, Wang Y, Chatterton ALD, Moleirinho S, Watson A, Hundal HS, Prystowsky MB, Gunn-Moore FJ, Reynolds PA. Crumbs 3b promotes tight junctions in an ezrin-dependent manner in mammalian cells. J Mol Cell Biol 2016; 8:439-455. [PMID: 27190314 PMCID: PMC5055084 DOI: 10.1093/jmcb/mjw020] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 01/19/2016] [Accepted: 01/25/2016] [Indexed: 01/30/2023] Open
Abstract
Crumbs 3 (CRB3) is a component of epithelial junctions, which has been implicated in apical-basal polarity, apical identity, apical stability, cell adhesion, and cell growth. CRB3 undergoes alternative splicing to yield two variants: CRB3a and CRB3b. Here, we describe novel data demonstrating that, as with previous studies on CRB3a, CRB3b also promotes the formation of tight junctions (TJs). However, significantly we demonstrate that the 4.1-ezrin-radixin-moesin-binding motif of CRB3b is required for CRB3b functionality and that ezrin binds to the FBM of CRB3b. Furthermore, we show that ezrin contributes to CRB3b functionality and the correct distribution of TJ proteins. We demonstrate that both CRB3 isoforms are required for the production of functionally mature TJs and also the localization of ezrin to the plasma membrane. Finally, we demonstrate that reduced CRB3b expression in head and neck squamous cell carcinoma (HNSCC) correlates with cytoplasmic ezrin, a biomarker for aggressive disease, and shows evidence that while CRB3a expression has no effect, low CRB3b and high cytoplasmic ezrin expression combined may be prognostic for HNSCC.
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Affiliation(s)
- Andrew M Tilston-Lünel
- Medical and Biological Sciences Building, School of Biology, University of St Andrews, St Andrews, KY16 9TF, UK
| | - Kathryn E Haley
- Medical and Biological Sciences Building, School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK
| | - Nicolas F Schlecht
- Department of Epidemiology & Population Health, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Yanhua Wang
- Department of Epidemiology & Population Health, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Abigail L D Chatterton
- Medical and Biological Sciences Building, School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK
| | - Susana Moleirinho
- Medical and Biological Sciences Building, School of Biology, University of St Andrews, St Andrews, KY16 9TF, UK.,Medical and Biological Sciences Building, School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK.,Present address: Scripps Research Institute, Jupiter, FL, USA
| | - Ailsa Watson
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | - Harinder S Hundal
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
| | | | - Frank J Gunn-Moore
- Medical and Biological Sciences Building, School of Biology, University of St Andrews, St Andrews, KY16 9TF, UK
| | - Paul A Reynolds
- Medical and Biological Sciences Building, School of Medicine, University of St Andrews, St Andrews, KY16 9TF, UK
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34
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Yang Y, Yang Y, Huang L, Zhai Y, Li J, Jiang Z, Gong B, Fang H, Kim R, Yang Z, Sundaresan P, Zhu X, Zhou Y. Whole exome sequencing identified novel CRB1 mutations in Chinese and Indian populations with autosomal recessive retinitis pigmentosa. Sci Rep 2016; 6:33681. [PMID: 27670293 PMCID: PMC5037368 DOI: 10.1038/srep33681] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2016] [Accepted: 08/31/2016] [Indexed: 01/02/2023] Open
Abstract
Retinitis pigmentosa (RP) is a leading cause of inherited blindness characterized by progressive degeneration of the retinal photoreceptor cells. This study aims to identify genetic mutations in a Chinese family RP-2236, an Indian family RP-IC-90 and 100 sporadic Indian individuals with autosomal recessive RP (arRP). Whole exome sequencing was performed on the index patients of RP-2236, RP-IC-90 and all of the 100 sporadic Indian patients. Direct Sanger sequencing was used to validate the mutations identified. Four novel mutations and one reported mutation in the crumbs homolog 1 (CRB1) gene, which has been known to cause severe retinal dystrophies, were identified. A novel homozygous splicing mutation c.2129-1G>C was found in the three patients In family RP-2236. A homozygous point mutation p.R664C was found in RP-IC-90. A novel homozygous mutation p.G1310C was identified in patient I-44, while novel compound heterozygous mutations p.N629D and p.A593T were found in patient I-7. All mutations described above were not present in the 1000 normal controls. In conclusion, we identified four novel mutations in CRB1 in a cohort of RP patients from the Chinese and Indian populations. Our data enlarges the CRB1 mutation spectrums and may provide new target loci for RP diagnose and treatment.
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Affiliation(s)
- Yin Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Sichuan Academy of Medical Sciences &Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Ophthalmology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
| | - Yeming Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Sichuan Academy of Medical Sciences &Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Institute of Laboratory Animal Sciences, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China.,Key Laboratory for NeuroInformation of Ministry of Education and Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Lulin Huang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Sichuan Academy of Medical Sciences &Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China
| | - Yaru Zhai
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Sichuan Academy of Medical Sciences &Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Jie Li
- Department of Ophthalmology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
| | - Zhilin Jiang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Sichuan Academy of Medical Sciences &Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China
| | - Bo Gong
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Sichuan Academy of Medical Sciences &Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China
| | - Hao Fang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Sichuan Academy of Medical Sciences &Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China
| | - Ramasamy Kim
- Retina-vitreous services, Aravind Eye Hospital, Madurai, Tamilnadu, India
| | - Zhenglin Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Sichuan Academy of Medical Sciences &Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Key Laboratory for NeuroInformation of Ministry of Education and Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Periasamy Sundaresan
- Department of Genetics, Aravind Medical Research Foundation, Aravind Eye Hospital, Madurai, Tamilnadu, India
| | - Xianjun Zhu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Sichuan Academy of Medical Sciences &Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Institute of Laboratory Animal Sciences, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China.,Key Laboratory for NeuroInformation of Ministry of Education and Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, Sichuan, China
| | - Yu Zhou
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, School of Medicine, Sichuan Academy of Medical Sciences &Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Department of Laboratory Medicine, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China.,Key Laboratory for NeuroInformation of Ministry of Education and Medicine Information Center, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, Sichuan, China
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35
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Gurudev N, Florek M, Corbeil D, Knust E. Prominent role of prominin in the retina. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 777:55-71. [PMID: 23161075 DOI: 10.1007/978-1-4614-5894-4_4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
Prominin molecules represent a new family of pentaspan membrane glycoproteins expressed throughout the animal kingdom. The name originates from its localization on membrane protrusion, such as microvilli, filopodia, lamellipodia, and microspikes. Following the original description in mouse and human, representative prominin members were found in fish (e.g., Danio rerio), amphibian (Ambystoma mexicanum, Xenopus laevis), worm (Caenorhabditis elegans), and flies (Drosophila melanogaster). Mammalian prominin-1 was identified as a marker of somatic and cancer stem cells and plays an essential role in the visual system, which contributed to increased interest of the medical field in this molecule. Here we summarize recent data from various fields, including Drosophila, which will aid to our understanding of its still elusive function.
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Affiliation(s)
- Nagananda Gurudev
- Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstr. 108, 01307, Dresden, Germany
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36
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Shah N, Damani MR, Zhu XS, Bedoukian EC, Bennett J, Maguire AM, Leroy BP. Isolated maculopathy associated with biallelic CRB1 mutations. Ophthalmic Genet 2016; 38:190-193. [PMID: 27096895 DOI: 10.3109/13816810.2016.1155225] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Neepa Shah
- a Division of Ophthalmology , Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA.,b Scheie Eye Institute, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Mausam R Damani
- a Division of Ophthalmology , Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA.,b Scheie Eye Institute, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Xiaosong Sonia Zhu
- a Division of Ophthalmology , Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA
| | - Emma C Bedoukian
- c Individualized Medical Genetics Center, Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA
| | - Jean Bennett
- b Scheie Eye Institute, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Albert M Maguire
- a Division of Ophthalmology , Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA.,b Scheie Eye Institute, University of Pennsylvania , Philadelphia , Pennsylvania , USA
| | - Bart P Leroy
- a Division of Ophthalmology , Children's Hospital of Philadelphia , Philadelphia , Pennsylvania , USA.,d Department of Ophthalmology & Center for Medical Genetics , Ghent University Hospital & Ghent University , Ghent , Belgium
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37
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Simmons AB, Merrill MM, Reed JC, Deans MR, Edwards MM, Fuerst PG. Defective Angiogenesis and Intraretinal Bleeding in Mouse Models With Disrupted Inner Retinal Lamination. Invest Ophthalmol Vis Sci 2016; 57:1563-77. [PMID: 27046121 PMCID: PMC4824390 DOI: 10.1167/iovs.15-18395] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/31/2016] [Indexed: 01/09/2023] Open
Abstract
PURPOSE Abnormal retinal angiogenesis leads to visual impairment and blindness. Understanding how retinal vessels develop normally has dramatically improved treatments for people with retinal vasculopathies, but additional information about development is required. Abnormal neuron patterning in the outer retina has been shown to result in abnormal vessel development and blindness, for example, in people and mouse models with Crumbs homologue 1 (CRB1) mutations. In this study, we report and characterize a mouse model of inner retinal lamination disruption and bleeding, the Down syndrome cell adhesion molecule (Dscam) mutant, and test how neuron-neurite placement within the inner retina guides development of intraretinal vessels. METHODS Bax mutant mice (increased neuron cell number), Dscam mutant mice (increased neuron cell number, disorganized lamination), Fat3 mutant mice (disorganized neuron lamination), and Dscam gain-of-function mice (Dscam(GOF)) (decreased neuron cell number) were used to manipulate neuron placement and number. Immunohistochemistry was used to assay organization of blood vessels, glia, and neurons. In situ hybridization was used to map the expression of angiogenic factors. RESULTS Significant changes in the organization of vessels within mutant retinas were found. Displaced neurons and microglia were associated with the attraction of vessels. Using Fat3 mutant and Dscam(GOF) retinas, we provide experimental evidence that vessel branching is induced at the neuron-neurite interface, but that other factors are required for full plexus layer formation. We further demonstrate that the displacement of neurons results in the mislocalization of angiogenic factors. CONCLUSIONS Inner retina neuron lamination is required for development of intraretinal vessels.
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Affiliation(s)
- Aaron B. Simmons
- University of Idaho, Department of Biological Sciences, Moscow, Idaho, United States
| | - Morgan M. Merrill
- University of Idaho, Department of Biological Sciences, Moscow, Idaho, United States
| | - Justin C. Reed
- University of Washington School of Medicine, WWAMI Medical Education Program, Moscow, Idaho, United States
| | - Michael R. Deans
- University of Utah School of Medicine, Division of Otolaryngology–Head and Neck Surgery, Salt Lake City, Utah, United States
- University of Utah School of Medicine, Department of Neurobiology and Anatomy, Salt Lake City, Utah, United States
| | - Malia M. Edwards
- Johns Hopkins University School of Medicine, Wilmer Eye Institute, Baltimore, Maryland, United States
| | - Peter G. Fuerst
- University of Idaho, Department of Biological Sciences, Moscow, Idaho, United States
- University of Washington School of Medicine, WWAMI Medical Education Program, Moscow, Idaho, United States
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38
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Dudok JJ, Murtaza M, Henrique Alves C, Rashbass P, Wijnholds J. Crumbs 2 prevents cortical abnormalities in mouse dorsal telencephalon. Neurosci Res 2016; 108:12-23. [PMID: 26802325 DOI: 10.1016/j.neures.2016.01.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Revised: 01/07/2016] [Accepted: 01/12/2016] [Indexed: 01/15/2023]
Abstract
The formation of a functionally integrated nervous system is dependent on a highly organized sequence of events that includes timely division and differentiation of progenitors. Several apical polarity proteins have been shown to play crucial roles during neurogenesis, however, the role of Crumbs 2 (CRB2) in cortical development has not previously been reported. Here, we show that conditional ablation of Crb2 in the murine dorsal telencephalon leads to defects in the maintenance of the apical complex. Furthermore, within the mutant dorsal telencephalon there is premature expression of differentiation proteins. We examined the physiological function of Crb2 on wild type genetic background as well as on background lacking Crb1. Telencephalon lacking CRB2 resulted in reduced levels of PALS1 and CRB3 from the apical complex, an increased number of mitotic cells and expanded neuronal domain. These defects are transient and therefore only result in rather mild cortical abnormalities. We show that CRB2 is required for maintenance of the apical polarity complex during development of the cortex and regulation of cell division, and that loss of CRB2 results in cortical abnormalities.
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Affiliation(s)
- Jacobus J Dudok
- Department of Neuromedical Genetics, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
| | - Mariyam Murtaza
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - C Henrique Alves
- Department of Neuromedical Genetics, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
| | - Pen Rashbass
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, United Kingdom
| | - Jan Wijnholds
- Department of Neuromedical Genetics, Netherlands Institute for Neuroscience, Meibergdreef 47, 1105 BA Amsterdam, The Netherlands; Department of Ophthalmology, Leiden University Medical Center, Albinusdreef 2, 2333 ZA Leiden, The Netherlands.
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39
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Markand S, Saul A, Tawfik A, Cui X, Rozen R, Smith SB. Mthfr as a modifier of the retinal phenotype of Crb1(rd8/rd8) mice. Exp Eye Res 2015; 145:164-172. [PMID: 26646559 DOI: 10.1016/j.exer.2015.11.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 10/21/2015] [Accepted: 11/20/2015] [Indexed: 10/22/2022]
Abstract
Mutations in crumb homologue 1 (CRB1) in humans are associated with Leber's congenital amaurosis (LCA) and retinitis pigmentosa (RP). There is no clear genotype-phenotype correlation for human CRB1 mutations in RP and LCA. The high variability in clinical features observed in CRB1 mutations suggests that environmental factors or genetic modifiers influence severity of CRB1 related retinopathies. Retinal degeneration 8 (rd8) is a spontaneous mutation in the Crb1 gene (Crb1(rdr/rd8)). Crb1(rdr/rd8) mice present with focal disruption in the outer retina manifesting as white spots on fundus examination. Mild retinal dysfunction with decreased b-wave amplitude has been reported in Crb1(rdr/rd8) mice at 18 months. Methylene tetrahydrofolate reductase (MTHFR) is a crucial enzyme of homocysteine metabolism. MTHFR mutations are prevalent in humans and are linked to a broad spectrum of disorders including cardiovascular and neurodegenerative diseases. We recently reported the retinal phenotype in Mthfr-deficient (Mthfr(+/-)) heterozygous mice. At 24 weeks the mice showed decreased RGC function, thinner nerve fiber layer, focal areas of vascular leakage and 20% fewer cells in the ganglion cell layer (GCL). Considering the variability in CRB1-related retinopathies and the high occurrence of human MTHFR mutations we evaluated whether Mthfr deficiency influences rd8 retinal phenotype. Mthfr heterozygous mice with rd8 mutations (Mthfr(+/-)(rd8/rd8)) and Crb(rd8/rd8) mice (Mthfr(+/+rd8/rd8)) mice were subjected to comprehensive retinal evaluation using ERG, fundoscopy, fluorescein angiography (FA), morphometric and retinal flat mount immunostaining analyses of isolectin-B4 at 8-54 wks. Assessment of retinal function revealed a significant decrease in the a-, b- and c-wave amplitudes in Mthfr(+/-)(rd8/rd8) mice at 52 wks. Fundoscopic evaluation demonstrated the presence of signature rd8 spots in Mthfr(+/+rd8/rd8) mice and an increase in the extent of these rd8 spots in Mthfr(+/-)(rd8/rd8) mice at 24 weeks and beyond. FA revealed marked vascular leakage, ischemia and vascular tortuosity in Mthfr(+/-)(rd8/rd8) mice at 24 and 52 weeks. Retinal dysplasia was observed in ∼14-33% Mthfr(+/-)(rd8/rd8) mice by morphometric analysis. This was accompanied by a ∼20% reduction in cells of the GCL of Mthfr(+/-)(rd8/rd8) mice at 24 and 52 weeks. Retinal flat mount immunostaining with isolectin-B4 showed neovascularization and loss of blood vessel integrity in Mthfr(+/-)(rd8/rd8) mice in contrast to mild vasculopathy in Mthfr(+/+rd8/rd8) mice. Taken together, our data support an earlier onset and worsened retinal phenotype when Mthfr and rd8 mutations coexist. Our study sets the stage for future studies to investigate the role of MTHFR deficiency in human CRB1 retinopathies.
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Affiliation(s)
- Shanu Markand
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; The James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA
| | - Alan Saul
- The James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA
| | - Amany Tawfik
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; The James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA
| | - Xuezhi Cui
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; The James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA
| | - Rima Rozen
- Departments of Pediatrics and Human Genetics, McGill University, Montreal, Canada
| | - Sylvia B Smith
- Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA; The James and Jean Culver Vision Discovery Institute, Georgia Regents University, Augusta, GA, USA; Department of Ophthalmology, Medical College of Georgia, Augusta University, Augusta, GA 30912, USA.
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40
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Paniagua AE, Herranz-Martín S, Jimeno D, Jimeno ÁM, López-Benito S, Carlos Arévalo J, Velasco A, Aijón J, Lillo C. CRB2 completes a fully expressed Crumbs complex in the Retinal Pigment Epithelium. Sci Rep 2015; 5:14504. [PMID: 26404741 PMCID: PMC4585915 DOI: 10.1038/srep14504] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 08/26/2015] [Indexed: 11/24/2022] Open
Abstract
The CRB proteins CRB1, CRB2 and CRB3 are members of the cell polarity complex Crumbs in mammals that together with Scribble and Par complexes stablish the polarity of a variety of cell types. Although many members of the Crumbs complex proteins are expressed in the retinal pigment epithelium (RPE), and even though the mRNA of CRB2 has been detected in ARPE-19 cells and in the RPE/Choroid, to date no CRB protein has yet been found in this tissue. To investigate this possibility, we generated an antibody that specifically recognize the mouse CRB2 protein, and we demonstrate the expression of CRB2 in mouse RPE. Confocal analysis shows that CRB2 is restricted to the apicolateral membrane of RPE cells, and more precisely, in the tight junctions. Our study identified CRB2 as the member of the CRB protein family that is present together with the rest of the components of the Crumbs complex in the RPE apico-lateral cell membrane. Considering that the functions of CRB proteins are decisive in the establishment and maintenance of cell-cell junctions in several epithelial-derived cell types, we believe that these findings are a relevant starting point for unraveling the functions that CRB2 might perform in the RPE.
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Affiliation(s)
- Antonio E Paniagua
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Saúl Herranz-Martín
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - David Jimeno
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Ángela M Jimeno
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Saray López-Benito
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Juan Carlos Arévalo
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Almudena Velasco
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - José Aijón
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
| | - Concepción Lillo
- Institute of Neurosciences of Castilla y León, IBSAL, Cell Biology and Pathology, University of Salamanca, 37007, Salamanca, Spain
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41
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CRB3A Controls the Morphology and Cohesion of Cancer Cells through Ehm2/p114RhoGEF-Dependent Signaling. Mol Cell Biol 2015. [PMID: 26217016 DOI: 10.1128/mcb.00673-15] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The transmembrane protein CRB3A controls epithelial cell polarization. Elucidating the molecular mechanisms of CRB3A function is essential as this protein prevents the epithelial-to-mesenchymal transition (EMT), which contributes to tumor progression. To investigate the functional impact of altered CRB3A expression in cancer cells, we expressed CRB3A in HeLa cells, which are devoid of endogenous CRB3A. While control HeLa cells display a patchy F-actin distribution, CRB3A-expressing cells form a circumferential actomyosin belt. This reorganization of the cytoskeleton is accompanied by a transition from an ameboid cell shape to an epithelial-cell-like morphology. In addition, CRB3A increases the cohesion of HeLa cells. To perform these functions, CRB3A recruits p114RhoGEF and its activator Ehm2 to the cell periphery using both functional motifs of its cytoplasmic tail and increases RhoA activation levels. ROCK1 and ROCK2 (ROCK1/2), which are critical effectors of RhoA, are also essential to modulate the cytoskeleton and cell shape downstream of CRB3A. Overall, our study highlights novel roles for CRB3A and deciphers the signaling pathway conferring to CRB3A the ability to fulfill these functions. Thereby, our data will facilitate further investigation of CRB3A functions and increase our understanding of the cellular defects associated with the loss of CRB3A expression in cancer cells.
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Johnson V, Xiang M, Chen Z, Junge HJ. Neurite Mistargeting and Inverse Order of Intraretinal Vascular Plexus Formation Precede Subretinal Vascularization in Vldlr Mutant Mice. PLoS One 2015; 10:e0132013. [PMID: 26177550 PMCID: PMC4503745 DOI: 10.1371/journal.pone.0132013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2015] [Accepted: 06/09/2015] [Indexed: 02/07/2023] Open
Abstract
In the retina blood vessels are required to support a high metabolic rate, however, uncontrolled vascular growth can lead to impaired vision and blindness. Subretinal vascularization (SRV), one type of pathological vessel growth, occurs in retinal angiomatous proliferation and proliferative macular telangiectasia. In these diseases SRV originates from blood vessels within the retina. We use mice with a targeted disruption in the Vldl-receptor (Vldlr) gene as a model to study SRV with retinal origin. We find that Vldlr mRNA is strongly expressed in the neuroretina, and we observe both vascular and neuronal phenotypes in Vldlr-/- mice. Unexpectedly, horizontal cell (HC) neurites are mistargeted prior to SRV in this model, and the majority of vascular lesions are associated with mistargeted neurites. In Foxn4-/- mice, which lack HCs and display reduced amacrine cell (AC) numbers, we find severe defects in intraretinal capillary development. However, SRV is not suppressed in Foxn4-/-;Vldlr-/- mice, which reveals that mistargeted HC neurites are not required for vascular lesion formation. In the absence of VLDLR, the intraretinal capillary plexuses form in an inverse order compared to normal development, and subsequent to this early defect, vascular proliferation is increased. We conclude that SRV in the Vldlr-/- model is associated with mistargeted neurites and that SRV is preceded by altered retinal vascular development.
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Affiliation(s)
- Verity Johnson
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado, 80309, United States of America
| | - Mengqing Xiang
- Center for Advanced Biotechnology and Medicine and Department of Pediatrics, Rutgers University-Robert Wood Johnson Medical School, Piscataway, New Jersey, 08901, United States of America
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, 54 South Xianlie Road, Guangzhou, 510060, China
| | - Zhe Chen
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado, 80309, United States of America
| | - Harald J. Junge
- Department of Molecular, Cellular, and Developmental Biology, University of Colorado, Boulder, Colorado, 80309, United States of America
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Stenkamp DL. Development of the Vertebrate Eye and Retina. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 134:397-414. [PMID: 26310167 DOI: 10.1016/bs.pmbts.2015.06.006] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The mature, functional, and healthy eye is generated by the coordinated regulatory interaction of numerous and diverse developing tissues. The neural retina of the eye must undergo the neurogenesis of multiple retinal cell types in the correct ratios and spatial patterns. This chapter provides an overview of retinal development, and includes a summary of the process of eye organogenesis, a discussion of major principles of retinal neurogenesis, and describes some of the key molecular factors critical for retinal development. Defects in many of these factors underlie diseases of the eye, and an understanding of the process of retinal development will be critical for successful future applications of regenerative therapies for eye disease.
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Affiliation(s)
- Deborah L Stenkamp
- Department of Biological Sciences, University of Idaho, Moscow, Idaho, USA.
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Lin WH, Asmann YW, Anastasiadis PZ. Expression of polarity genes in human cancer. Cancer Inform 2015; 14:15-28. [PMID: 25991909 PMCID: PMC4390136 DOI: 10.4137/cin.s18964] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 02/10/2015] [Accepted: 02/12/2015] [Indexed: 01/01/2023] Open
Abstract
Polarity protein complexes are crucial for epithelial apical–basal polarity and directed cell migration. Since alterations of these processes are common in cancer, polarity proteins have been proposed to function as tumor suppressors or oncogenic promoters. Here, we review the current understanding of polarity protein functions in epithelial homeostasis, as well as tumor formation and progression. As most previous studies focused on the function of single polarity proteins in simplified model systems, we used a genomics approach to systematically examine and identify the expression profiles of polarity genes in human cancer. The expression profiles of polarity genes were distinct in different human tissues and classified cancer types. Additionally, polarity expression profiles correlated with disease progression and aggressiveness, as well as with identified cancer types, where specific polarity genes were commonly altered. In the case of Scribble, gene expression analysis indicated its common amplification and upregulation in human cancer, suggesting a tumor promoting function.
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Affiliation(s)
- Wan-Hsin Lin
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, USA
| | - Yan W Asmann
- Department of Health Sciences Research, Mayo Clinic, Jacksonville, FL, USA
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Abstract
Apico-basal polarity is a cardinal molecular feature of adult eukaryotic epithelial cells and appears to be involved in several key cellular processes including polarized cell migration and maintenance of tissue architecture. Epithelial cell polarity is maintained by three well-conserved polarity complexes, namely, PAR, Crumbs and SCRIB. The location and interaction between the components of these complexes defines distinct structural domains of epithelial cells. Establishment and maintenance of apico-basal polarity is regulated through various conserved cell signalling pathways including TGF beta, Integrin and WNT signalling. Loss of cell polarity is a hallmark for carcinoma, and its underlying molecular mechanism is beginning to emerge from studies on model organisms and cancer cell lines. Moreover, deregulated expression of apico-basal polarity complex components has been reported in human tumours. In this review, we provide an overview of the apico-basal polarity complexes and their regulation, their role in cell migration, and finally their involvement in carcinogenesis.
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Affiliation(s)
- Mohammed Khursheed
- Centre for DNA Fingerprinting and Diagnostics (CDFD), Nampally, Hyderabad 500 001, India
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Luhmann UFO, Carvalho LS, Holthaus SMK, Cowing JA, Greenaway S, Chu CJ, Herrmann P, Smith AJ, Munro PMG, Potter P, Bainbridge JWB, Ali RR. The severity of retinal pathology in homozygous Crb1rd8/rd8 mice is dependent on additional genetic factors. Hum Mol Genet 2014; 24:128-41. [PMID: 25147295 PMCID: PMC4262495 DOI: 10.1093/hmg/ddu424] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Understanding phenotype–genotype correlations in retinal degeneration is a major challenge. Mutations in CRB1 lead to a spectrum of autosomal recessive retinal dystrophies with variable phenotypes suggesting the influence of modifying factors. To establish the contribution of the genetic background to phenotypic variability associated with the Crb1rd8/rd8 mutation, we compared the retinal pathology of Crb1rd8/rd8/J inbred mice with that of two Crb1rd8/rd8 lines backcrossed with C57BL/6JOlaHsd mice. Topical endoscopic fundal imaging and scanning laser ophthalmoscopy fundus images of all three Crb1rd8/rd8 lines showed a significant increase in the number of inferior retinal lesions that was strikingly variable between the lines. Optical coherence tomography, semithin, ultrastructural morphology and assessment of inflammatory and vascular marker by immunohistochemistry and quantitative reverse transcriptase-polymerase chain reaction revealed that the lesions were associated with photoreceptor death, Müller and microglia activation and telangiectasia-like vascular remodelling—features that were stable in the inbred, variable in the second, but virtually absent in the third Crb1rd8/rd8 line, even at 12 months of age. This suggests that the Crb1rd8/rd8 mutation is necessary, but not sufficient for the development of these degenerative features. By whole-genome SNP analysis of the genotype–phenotype correlation, a candidate region on chromosome 15 was identified. This may carry one or more genetic modifiers for the manifestation of the retinal pathology associated with mutations in Crb1. This study also provides insight into the nature of the retinal vascular lesions that likely represent a clinical correlate for the formation of retinal telangiectasia or Coats-like vasculopathy in patients with CRB1 mutations that are thought to depend on such genetic modifiers.
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Affiliation(s)
| | | | - Sophia-Martha Kleine Holthaus
- Department of Genetics and MRC Laboratory for Molecular Cell Biology, University College London, London WC1E 6BT, UK
| | | | - Simon Greenaway
- Imaging Unit, UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | | | | | | | - Peter M G Munro
- Imaging Unit, UCL Institute of Ophthalmology, London EC1V 9EL, UK
| | - Paul Potter
- Mammalian Genetics Unit, MRC Harwell, Oxfordshire OX11 ORD, UK and
| | - James W B Bainbridge
- Department of Genetics and NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London EC1V 2PD, UK
| | - Robin R Ali
- Department of Genetics and NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London EC1V 2PD, UK
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Abstract
Mutations in the CRB1 gene cause severe retinal degenerations, which may present as Leber congenital amaurosis, early onset retinal dystrophy, retinitis pigmentosa, or cone-rod dystrophy. Some clinical features should alert the ophthalmologist to the possibility of CRB1 disease. These features are nummular pigmentation of the retina, atrophic macula, retinal degeneration associated with Coats disease, and a unique form of retinitis pigmentosa named para-arteriolar preservation of the retinal pigment epithelium (PPRPE). Retinal degenerations associated with nanophthalmos and hyperopia, or with keratoconus, can serve as further clinical cues to mutations in CRB1. Despite this, no clear genotype-phenotype relationship has been established in CRB1 disease. In CRB1-disease, as in other inherited retinal degenerations (IRDs), it is essential to diagnose the specific disease-causing gene for the disease as genetic therapy has progressed considerably in the last few years and might be applicable.
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Affiliation(s)
- Miriam Ehrenberg
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston , Massachusetts , USA
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Abstract
A unique feature of humans is the complexity of our central nervous system. A fully functional brain requires that billions of neurons make specific contacts in a highly coordinated way, an issue that is still not well understood. The neural retina constitutes an excellent system with which to analyze key aspects of neurogenesis and circuit formation in the central nervous system. Here, we provide an overview of retinal neurogenesis in vertebrates and discuss implications of the developmental mechanisms involved for regenerative therapy approaches.
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Affiliation(s)
- Lázaro Centanin
- Department of Developmental Biology/Physiology, Centre for Organismal Studies (COS) Heidelberg, Im Neuenheimer Feld 230, 69120 Heidelberg, Germany
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Cordovez JA, Traboulsi EI, Capasso JE, Sadagopan KA, Ganesh A, Rychwalski PJ, Neely KA, Brodie SE, Levin AV. Retinal Dystrophy with Intraretinal Cystoid Spaces Associated with Mutations in the Crumbs Homologue (CRB1) Gene. Ophthalmic Genet 2014; 36:257-64. [DOI: 10.3109/13816810.2014.881505] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Alves CH, Pellissier LP, Wijnholds J. The CRB1 and adherens junction complex proteins in retinal development and maintenance. Prog Retin Eye Res 2014; 40:35-52. [PMID: 24508727 DOI: 10.1016/j.preteyeres.2014.01.001] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Revised: 01/21/2014] [Accepted: 01/27/2014] [Indexed: 12/30/2022]
Abstract
The early developing retinal neuroepithelium is composed of multipotent retinal progenitor cells that differentiate in a time specific manner, giving rise to six major types of neuronal and one type of glial cells. These cells migrate and organize in three distinct nuclear layers divided by two plexiform layers. Apical and adherens junction complexes have a crucial role in this process by the establishment of polarity and adhesion. Changes in these complexes disturb the spatiotemporal aspects of retinogenesis, leading to retinal degeneration resulting in mild or severe impairment of retinal function and vision. In this review, we summarize the mouse models for the different members of the apical and adherens junction protein complexes and describe the main features of their retinal phenotypes. The knowledge acquired from the different mutant animals for these proteins corroborate their importance in retina development and maintenance of normal retinal structure and function. More recently, several studies have tried to unravel the connection between the apical proteins, important cellular signaling pathways and their relation in retina development. Still, the mechanisms by which these proteins function remain largely unknown. Here, we hypothesize how the mammalian apical CRB1 complex might control retinogenesis and prevents onset of Leber congenital amaurosis or retinitis pigmentosa.
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Affiliation(s)
- Celso Henrique Alves
- Department of Neuromedical Genetics, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
| | - Lucie P Pellissier
- Department of Neuromedical Genetics, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Meibergdreef 47, 1105 BA Amsterdam, The Netherlands
| | - Jan Wijnholds
- Department of Neuromedical Genetics, The Netherlands Institute for Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), Meibergdreef 47, 1105 BA Amsterdam, The Netherlands.
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