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Mercey O, Mukherjee S, Guichard P, Hamel V. The molecular architecture of the ciliary transition zones. Curr Opin Cell Biol 2024; 88:102361. [PMID: 38648677 DOI: 10.1016/j.ceb.2024.102361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 03/28/2024] [Accepted: 03/30/2024] [Indexed: 04/25/2024]
Abstract
Cilia and flagella are specialized eukaryotic organelles projecting from the surface of eukaryotic cells that play a central role in various physiological processes, including cell motility, sensory perception, and signal transduction. At the base of these structures lies the ciliary transition zone, a pivotal region that functions as a gatekeeper and communication hub for ciliary activities. Despite its crucial role, the intricacies of its architecture remain poorly understood, especially given the variations in its organization across different cell types and species. In this review, we explore the molecular architecture of the ciliary transition zone, with a particular focus on recent findings obtained using cryotomography and super-resolution imaging techniques.
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Affiliation(s)
- Olivier Mercey
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Souradip Mukherjee
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Paul Guichard
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland.
| | - Virginie Hamel
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland.
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2
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McDonald A, Wijnholds J. Retinal Ciliopathies and Potential Gene Therapies: A Focus on Human iPSC-Derived Organoid Models. Int J Mol Sci 2024; 25:2887. [PMID: 38474133 DOI: 10.3390/ijms25052887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024] Open
Abstract
The human photoreceptor function is dependent on a highly specialised cilium. Perturbation of cilial function can often lead to death of the photoreceptor and loss of vision. Retinal ciliopathies are a genetically diverse range of inherited retinal disorders affecting aspects of the photoreceptor cilium. Despite advances in the understanding of retinal ciliopathies utilising animal disease models, they can often lack the ability to accurately mimic the observed patient phenotype, possibly due to structural and functional deviations from the human retina. Human-induced pluripotent stem cells (hiPSCs) can be utilised to generate an alternative disease model, the 3D retinal organoid, which contains all major retinal cell types including photoreceptors complete with cilial structures. These retinal organoids facilitate the study of disease mechanisms and potential therapies in a human-derived system. Three-dimensional retinal organoids are still a developing technology, and despite impressive progress, several limitations remain. This review will discuss the state of hiPSC-derived retinal organoid technology for accurately modelling prominent retinal ciliopathies related to genes, including RPGR, CEP290, MYO7A, and USH2A. Additionally, we will discuss the development of novel gene therapy approaches targeting retinal ciliopathies, including the delivery of large genes and gene-editing techniques.
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Affiliation(s)
- Andrew McDonald
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands
| | - Jan Wijnholds
- Department of Ophthalmology, Leiden University Medical Center (LUMC), 2333 ZC Leiden, The Netherlands
- Netherlands Institute of Neuroscience, Royal Netherlands Academy of Arts and Sciences (KNAW), 1105 BA Amsterdam, The Netherlands
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3
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Moran AL, Louzao-Martinez L, Norris DP, Peters DJM, Blacque OE. Transport and barrier mechanisms that regulate ciliary compartmentalization and ciliopathies. Nat Rev Nephrol 2024; 20:83-100. [PMID: 37872350 DOI: 10.1038/s41581-023-00773-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/19/2023] [Indexed: 10/25/2023]
Abstract
Primary cilia act as cell surface antennae, coordinating cellular responses to sensory inputs and signalling molecules that regulate developmental and homeostatic pathways. Cilia are therefore critical to physiological processes, and defects in ciliary components are associated with a large group of inherited pleiotropic disorders - known collectively as ciliopathies - that have a broad spectrum of phenotypes and affect many or most tissues, including the kidney. A central feature of the cilium is its compartmentalized structure, which imparts its unique molecular composition and signalling environment despite its membrane and cytosol being contiguous with those of the cell. Such compartmentalization is achieved via active transport pathways that bring protein cargoes to and from the cilium, as well as gating pathways at the ciliary base that establish diffusion barriers to protein exchange into and out of the organelle. Many ciliopathy-linked proteins, including those involved in kidney development and homeostasis, are components of the compartmentalizing machinery. New insights into the major compartmentalizing pathways at the cilium, namely, ciliary gating, intraflagellar transport, lipidated protein flagellar transport and ciliary extracellular vesicle release pathways, have improved our understanding of the mechanisms that underpin ciliary disease and associated renal disorders.
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Affiliation(s)
- Ailis L Moran
- School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland
| | - Laura Louzao-Martinez
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | | | - Dorien J M Peters
- Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Dublin, Ireland.
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Cideciyan AV, Jacobson SG, Ho AC, Swider M, Sumaroka A, Roman AJ, Wu V, Russell RC, Viarbitskaya I, Garafalo AV, Schwartz MR, Girach A. Durable vision improvement after a single intravitreal treatment with antisense oligonucleotide in CEP290-LCA: Replication in two eyes. Am J Ophthalmol Case Rep 2023; 32:101873. [PMID: 37388818 PMCID: PMC10302566 DOI: 10.1016/j.ajoc.2023.101873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/15/2023] [Accepted: 06/11/2023] [Indexed: 07/01/2023] Open
Abstract
Purpose An intravitreally injected antisense oligonucleotide, sepofarsen, was designed to modulate splicing within retinas of patients with severe vision loss due to deep intronic c.2991 + 1655A > G variant in the CEP290 gene. A previous report showed vision improvements following a single injection in one eye with unexpected durability lasting at least 15 months. The current study evaluated durability of efficacy beyond 15 months in the previously treated left eye. In addition, peak efficacy and durability were evaluated in the treatment-naive right eye, and re-injection of the left eye 4 years after the first injection. Observations Visual function was evaluated with best corrected standard and low-luminance visual acuities, microperimetry, dark-adapted chromatic perimetry, and full-field sensitivity testing. Retinal structure was evaluated with OCT imaging. At the fovea, all visual function measures and IS/OS intensity of the OCT showed transient improvements peaking at 3-6 months, remaining better than baseline at ∼2 years, and returning to baseline by 3-4 years after each single injection. Conclusions and Importance These results suggest that sepofarsen reinjection intervals may need to be longer than 2 years.
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Affiliation(s)
- Artur V. Cideciyan
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Samuel G. Jacobson
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Allen C. Ho
- Wills Eye Hospital, Thomas Jefferson University, Philadelphia, USA
| | - Malgorzata Swider
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alexander Sumaroka
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alejandro J. Roman
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Vivian Wu
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Robert C. Russell
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Iryna Viarbitskaya
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Alexandra V. Garafalo
- Scheie Eye Institute, Department of Ophthalmology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
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Khan S, Focșa IO, Budișteanu M, Stoica C, Nedelea F, Bohîlțea L, Caba L, Butnariu L, Pânzaru M, Rusu C, Jurcă C, Chirita-Emandi A, Bănescu C, Abbas W, Sadeghpour A, Baig SM, Bălgrădean M, Davis EE. Exome sequencing in a Romanian Bardet-Biedl syndrome cohort revealed an overabundance of causal BBS12 variants. Am J Med Genet A 2023; 191:2376-2391. [PMID: 37293956 PMCID: PMC10524726 DOI: 10.1002/ajmg.a.63322] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/16/2023] [Accepted: 05/26/2023] [Indexed: 06/10/2023]
Abstract
Bardet-Biedl syndrome (BBS), is an emblematic ciliopathy hallmarked by pleiotropy, phenotype variability, and extensive genetic heterogeneity. BBS is a rare (~1/140,000 to ~1/160,000 in Europe) autosomal recessive pediatric disorder characterized by retinal degeneration, truncal obesity, polydactyly, cognitive impairment, renal dysfunction, and hypogonadism. Twenty-eight genes involved in ciliary structure or function have been implicated in BBS, and explain the molecular basis for ~75%-80% of individuals. To investigate the mutational spectrum of BBS in Romania, we ascertained a cohort of 24 individuals in 23 families. Following informed consent, we performed proband exome sequencing (ES). We detected 17 different putative disease-causing single nucleotide variants or small insertion-deletions and two pathogenic exon disruptive copy number variants in known BBS genes in 17 pedigrees. The most frequently impacted genes were BBS12 (35%), followed by BBS4, BBS7, and BBS10 (9% each) and BBS1, BBS2, and BBS5 (4% each). Homozygous BBS12 p.Arg355* variants were present in seven pedigrees of both Eastern European and Romani origin. Our data show that although the diagnostic rate of BBS in Romania is likely consistent with other worldwide cohorts (74%), we observed a unique distribution of causal BBS genes, including overrepresentation of BBS12 due to a recurrent nonsense variant, that has implications for regional diagnostics.
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Affiliation(s)
- Sheraz Khan
- Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
- Human Molecular Genetics Lab, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE-C), Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Ina Ofelia Focșa
- University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania
- Cytogenomic Medical Laboratory, Bucharest, Romania
| | - Magdalena Budișteanu
- Psychiatry Research Laboratory, "Prof. Dr. Alexandru Obregia" Clinical Hospital of Psychiatry, Bucharest, Romania
- Medical Genetic Laboratory, "Victor Babeș" National Institute of Pathology, Bucharest, Romania
- Department of Medical Genetics, Faculty of Medicine, "Titu Maiorescu" University, Bucharest, Romania
| | - Cristina Stoica
- University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania
- Department of Pediatrics, Clinical Institute Fundeni, Bucharest, Romania
| | - Florina Nedelea
- University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania
- Genetics Department, Clinical Hospital Filantropia, Bucharest, Romania
| | | | - Lavinia Caba
- Department of Medical Genetics, "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania
| | - Lăcrămioara Butnariu
- Department of Medical Genetics, "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania
- Regional Medical Genetics Centre, "Sf. Maria" Children's Hospital, Iași, Romania
| | - Monica Pânzaru
- Department of Medical Genetics, "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania
- Regional Medical Genetics Centre, "Sf. Maria" Children's Hospital, Iași, Romania
| | - Cristina Rusu
- Department of Medical Genetics, "Grigore T. Popa" University of Medicine and Pharmacy, Iași, Romania
- Regional Medical Genetics Centre, "Sf. Maria" Children's Hospital, Iași, Romania
| | - Claudia Jurcă
- Department of Genetics, Faculty of Medicine and Pharmacy, University of Oradea, Oradea, Romania
- Department of Pediatrics, "Dr. Gavril Curteanu" Municipal Clinical Hospital, Oradea, Romania
| | - Adela Chirita-Emandi
- Emergency Hospital for Children Louis Turcanu, Regional Center of Medical Genetics Timis, Timisoara, Romania
- Victor Babes University of Medicine and Pharmacy Timisoara, Department of Microscopic Morphology Genetics, Center for Genomic Medicine, Timisoara, Romania
| | - Claudia Bănescu
- "George Emil Palade" University of Medicine, Pharmacy, Sciences and Technology, Târgu Mureş, Romania
| | - Wasim Abbas
- Human Molecular Genetics Lab, Health Biotechnology Division, National Institute for Biotechnology and Genetic Engineering (NIBGE-C), Faisalabad, Pakistan
- Pakistan Institute of Engineering and Applied Sciences (PIEAS), Islamabad, Pakistan
| | - Azita Sadeghpour
- Center for Human Disease Modeling, Duke University Medical Center, Durham, North Carolina, USA
- Duke Precision Medicine Program, Department of Medicine, Division of General Internal Medicine, Duke University Medical Center, Durham, NC, USA
| | - Shahid Mahmood Baig
- Pakistan Science Foundation (PSF), Islamabad, Pakistan
- Department of Biological and Biomedical Sciences, Agha Khan University Karachi, Karachi, Pakistan
| | - Mihaela Bălgrădean
- University of Medicine and Pharmacy "Carol Davila", Bucharest, Romania
- Department of Pediatrics and Pediatric Nephrology, Emergency Clinical Hospital for Children "Maria Skłodowska Curie", Bucharest, Romania
| | - Erica E Davis
- Stanley Manne Children's Research Institute, Ann & Robert H. Lurie Children's Hospital of Chicago, Chicago, Illinois, USA
- Department of Pediatrics and Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
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Tian X, Zhao H, Zhou J. Organization, functions, and mechanisms of the BBSome in development, ciliopathies, and beyond. eLife 2023; 12:e87623. [PMID: 37466224 DOI: 10.7554/elife.87623] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 07/06/2023] [Indexed: 07/20/2023] Open
Abstract
The BBSome is an octameric protein complex that regulates ciliary transport and signaling. Mutations in BBSome subunits are closely associated with ciliary defects and lead to ciliopathies, notably Bardet-Biedl syndrome. Over the past few years, there has been significant progress in elucidating the molecular organization and functions of the BBSome complex. An improved understanding of BBSome-mediated biological events and molecular mechanisms is expected to help advance the development of diagnostic and therapeutic approaches for BBSome-related diseases. Here, we review the current literature on the structural assembly, transport regulation, and molecular functions of the BBSome, emphasizing its roles in cilium-related processes. We also provide perspectives on the pathological role of the BBSome in ciliopathies as well as how these can be exploited for therapeutic benefit.
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Affiliation(s)
- Xiaoyu Tian
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Huijie Zhao
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, China
| | - Jun Zhou
- Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, College of Life Sciences, Shandong Normal University, Jinan, China
- State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University, Tianjin, China
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Grabinski SE, Parsana D, Perkins BD. Comparative analysis of transcriptional changes in zebrafish cep290 and bbs2 mutants by RNA-seq reveals upregulation of inflammatory and stress-related pathways. Front Mol Neurosci 2023; 16:1148840. [PMID: 37293546 PMCID: PMC10244513 DOI: 10.3389/fnmol.2023.1148840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 05/09/2023] [Indexed: 06/10/2023] Open
Abstract
Acute injury to the adult zebrafish retina triggers the release of pro-inflammatory cytokines and growth factors that stimulate multiple gene regulatory networks, which ultimately stimulate Müller glia to proliferate and regenerate neurons. In contrast, zebrafish carrying mutations in cep290 or bbs2 undergo progressive loss of cone photoreceptors and exhibit signs of microglia activation and inflammation, but the mutants fail to stimulate a regeneration response. To identify transcriptional changes that occur in zebrafish mutants undergoing progressive photoreceptor degeneration, RNA-seq transcriptional profiling was performed on cep290-/- and bbs2-/- retinas. The PANTHER Classification System was used to identify biological processes and signaling pathways that were differentially expressed between mutants and wild-type siblings during degeneration. As expected, genes associated with phototransduction were downregulated in cep290 and bbs2 mutants compared to wild-type siblings. Although both cep290 and bbs2 mutants undergo proliferation of rod precursors in response to retinal degeneration, the process of negatively regulating proliferation is enriched for upregulated genes, and this negative regulation may restrict proliferation of Müller glia and inhibit regeneration. A total of 815 differentially expressed genes (DEGs) were shared by cep290 and bbs2 retinas. Genes in pathways associated with inflammation, apoptosis, stress response, and PDGF signaling were overrepresented. Identifying the genes and biological pathways that are common in zebrafish models of inherited retinal degeneration provides a foundation for future studies on the mechanisms that regulate cell death as well as processes that prohibit Müller cell reprogramming or proliferation in a model capable of retinal regeneration. The pathways will provide targets for future interventions that may promote successful regeneration of lost photoreceptors.
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Affiliation(s)
- Sarah E. Grabinski
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Dhwani Parsana
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Brian D. Perkins
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, United States
- Department of Ophthalmology, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, United States
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, United States
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Devlin L, Dhondurao Sudhindar P, Sayer JA. Renal ciliopathies: promising drug targets and prospects for clinical trials. Expert Opin Ther Targets 2023; 27:325-346. [PMID: 37243567 DOI: 10.1080/14728222.2023.2218616] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 05/12/2023] [Accepted: 05/23/2023] [Indexed: 05/29/2023]
Abstract
INTRODUCTION Renal ciliopathies represent a collection of genetic disorders characterized by deficiencies in the biogenesis, maintenance, or functioning of the ciliary complex. These disorders, which encompass autosomal dominant polycystic kidney disease (ADPKD), autosomal recessive polycystic kidney disease (ARPKD), and nephronophthisis (NPHP), typically result in cystic kidney disease, renal fibrosis, and a gradual deterioration of kidney function, culminating in kidney failure. AREAS COVERED Here we review the advances in basic science and clinical research into renal ciliopathies which have yielded promising small compounds and drug targets, within both preclinical studies and clinical trials. EXPERT OPINION Tolvaptan is currently the sole approved treatment option available for ADPKD patients, while no approved treatment alternatives exist for ARPKD or NPHP patients. Clinical trials are presently underway to evaluate additional medications in ADPKD and ARPKD patients. Based on preclinical models, other potential therapeutic targets for ADPKD, ARPKD, and NPHP look promising. These include molecules targeting fluid transport, cellular metabolism, ciliary signaling and cell-cycle regulation. There is a real and urgent clinical need for translational research to bring novel treatments to clinical use for all forms of renal ciliopathies to reduce kidney disease progression and prevent kidney failure.
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Affiliation(s)
- Laura Devlin
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - Praveen Dhondurao Sudhindar
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
| | - John A Sayer
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle Upon Tyne, UK
- Renal Services, Newcastle Upon Tyne Hospitals NHS Foundation Trust, Newcastle Upon Tyne, UK
- NIHR Newcastle Biomedical Research Centre, Newcastle Upon Tyne, UK
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Delvallée C, Dollfus H. Retinal Degeneration Animal Models in Bardet-Biedl Syndrome and Related Ciliopathies. Cold Spring Harb Perspect Med 2023; 13:13/1/a041303. [PMID: 36596648 PMCID: PMC9808547 DOI: 10.1101/cshperspect.a041303] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Retinal degeneration due to photoreceptor ciliary-related proteins dysfunction accounts for more than 25% of all inherited retinal dystrophies. The cilium, being an evolutionarily conserved and ubiquitous organelle implied in many cellular functions, can be investigated by way of many models from invertebrate models to nonhuman primates, all these models have massively contributed to the pathogenesis understanding of human ciliopathies. Taking the Bardet-Biedl syndrome (BBS) as an emblematic example as well as other related syndromic ciliopathies, the contribution of a wide range of models has enabled to characterize the role of the BBS proteins in the archetypical cilium but also at the level of the connecting cilium of the photoreceptors. There are more than 24 BBS genes encoding for proteins that form different complexes such as the BBSome and the chaperone proteins complex. But how they lead to retinal degeneration remains a matter of debate with the possible accumulation of proteins in the inner segment and/or accumulation of unwanted proteins in the outer segment that cannot return in the inner segment machinery. Many BBS proteins (but not the chaperonins for instance) can be modeled in primitive organisms such as Paramecium, Chlamydomonas reinardtii, Trypanosoma brucei, and Caenorhabditis elegans These models have enabled clarifying the role of a subset of BBS proteins in the primary cilium as well as their relations with other modules such as the intraflagellar transport (IFT) module, the nephronophthisis (NPHP) module, or the Meckel-Gruber syndrome (MKS)/Joubert syndrome (JBTS) module mostly involved with the transition zone of the primary cilia. Assessing the role of the primary cilia structure of the connecting cilium of the photoreceptor cells has been very much studied by way of zebrafish modeling (Danio rerio) as well as by a plethora of mouse models. More recently, large animal models have been described for three BBS genes and one nonhuman primate model in rhesus macaque for BBS7 In completion to animal models, human cell models can now be used notably thanks to gene editing and the use of induced pluripotent stem cells (iPSCs). All these models are not only important for pathogenesis understanding but also very useful for studying therapeutic avenues, their pros and cons, especially for gene replacement therapy as well as pharmacological triggers.
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Affiliation(s)
- Clarisse Delvallée
- Laboratoire de Génétique Médicale UMRS1112, Centre de Recherche Biomédicale de Strasbourg, CRBS, Institut de Génétique Médicale d'Alsace, IGMA, Strasbourg 67000, France
| | - Hélène Dollfus
- Laboratoire de Génétique Médicale UMRS1112, Centre de Recherche Biomédicale de Strasbourg, CRBS, Institut de Génétique Médicale d'Alsace, IGMA, Strasbourg 67000, France
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10
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Oki Y, Katsuma A, Okabe M, Watanabe M, Sagasaki M, Takahashi D, Kimura A, Kato J, Ueda H, Hataya H, Fujimaru T, Mori T, Sohara E, Uchida S, Miyazaki Y, Yokoo T. Different Clinical Courses of Nephronophthisis in Dizygotic Twins. Intern Med 2023; 62:87-90. [PMID: 35676033 PMCID: PMC9876724 DOI: 10.2169/internalmedicine.8707-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Siblings with nephronophthisis occasionally show different clinical courses; however, the reasons for this remain unclear. We herein report cases of nephronophthisis in a pair of dizygotic twins with different clinical courses. The brother developed end-stage kidney disease at 17 years old; however, his sister did not show kidney insufficiency. Kidney biopsies revealed severe tubulointerstitial damage at 14 and 22 years old in the brother and sister, respectively. Both had a homozygous NPHP1 deletion with different heterozygous mutations related to hereditary cystic kidney disease. Since the dizygotic twins were exposed to similar environmental factors, genetic factors may have influenced their clinical course more strongly than environmental factors.
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Affiliation(s)
- Yutaro Oki
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Japan
| | - Ai Katsuma
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Japan
| | - Masahiro Okabe
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Japan
| | - Mao Watanabe
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Japan
| | - Makoto Sagasaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Japan
| | - Daisuke Takahashi
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Japan
| | - Ai Kimura
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Japan
| | - Junichiro Kato
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Japan
| | - Hiroyuki Ueda
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Japan
| | - Hiroshi Hataya
- Department of Nephrology and Rheumatology, Tokyo Metropolitan Children's Medical Center, Japan
| | - Takuya Fujimaru
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan
| | - Takayasu Mori
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan
| | - Eisei Sohara
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan
| | - Shinichi Uchida
- Department of Nephrology, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Japan
| | - Yoichi Miyazaki
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Japan
| | - Takashi Yokoo
- Division of Nephrology and Hypertension, Department of Internal Medicine, Jikei University School of Medicine, Japan
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Park K, Leroux MR. Composition, organization and mechanisms of the transition zone, a gate for the cilium. EMBO Rep 2022; 23:e55420. [PMID: 36408840 PMCID: PMC9724682 DOI: 10.15252/embr.202255420] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 08/08/2022] [Accepted: 10/31/2022] [Indexed: 11/22/2022] Open
Abstract
The cilium evolved to provide the ancestral eukaryote with the ability to move and sense its environment. Acquiring these functions required the compartmentalization of a dynein-based motility apparatus and signaling proteins within a discrete subcellular organelle contiguous with the cytosol. Here, we explore the potential molecular mechanisms for how the proximal-most region of the cilium, termed transition zone (TZ), acts as a diffusion barrier for both membrane and soluble proteins and helps to ensure ciliary autonomy and homeostasis. These include a unique complement and spatial organization of proteins that span from the microtubule-based axoneme to the ciliary membrane; a protein picket fence; a specialized lipid microdomain; differential membrane curvature and thickness; and lastly, a size-selective molecular sieve. In addition, the TZ must be permissive for, and functionally integrates with, ciliary trafficking systems (including intraflagellar transport) that cross the barrier and make the ciliary compartment dynamic. The quest to understand the TZ continues and promises to not only illuminate essential aspects of human cell signaling, physiology, and development, but also to unravel how TZ dysfunction contributes to ciliopathies that affect multiple organ systems, including eyes, kidney, and brain.
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Affiliation(s)
- Kwangjin Park
- Department of Molecular Biology and BiochemistrySimon Fraser UniversityBurnabyBCCanada
- Centre for Cell Biology, Development, and DiseaseSimon Fraser UniversityBurnabyBCCanada
- Present address:
Terry Fox LaboratoryBC CancerVancouverBCCanada
- Present address:
Department of Medical GeneticsUniversity of British ColumbiaVancouverBCCanada
| | - Michel R Leroux
- Department of Molecular Biology and BiochemistrySimon Fraser UniversityBurnabyBCCanada
- Centre for Cell Biology, Development, and DiseaseSimon Fraser UniversityBurnabyBCCanada
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12
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Kruczek K, Qu Z, Welby E, Shimada H, Hiriyanna S, English MA, Zein WM, Brooks BP, Swaroop A. In vitro modeling and rescue of ciliopathy associated with IQCB1/NPHP5 mutations using patient-derived cells. Stem Cell Reports 2022; 17:2172-2186. [PMID: 36084637 PMCID: PMC9561628 DOI: 10.1016/j.stemcr.2022.08.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 08/12/2022] [Accepted: 08/12/2022] [Indexed: 11/26/2022] Open
Abstract
Mutations in the IQ calmodulin-binding motif containing B1 (IQCB1)/NPHP5 gene encoding the ciliary protein nephrocystin 5 cause early-onset blinding disease Leber congenital amaurosis (LCA), together with kidney dysfunction in Senior-Løken syndrome. For in vitro disease modeling, we obtained dermal fibroblasts from patients with NPHP5-LCA that were reprogrammed into induced pluripotent stem cells (iPSCs) and differentiated into retinal pigment epithelium (RPE) and retinal organoids. Patient fibroblasts and RPE demonstrated aberrantly elongated ciliary axonemes. Organoids revealed impaired development of outer segment structures, which are modified primary cilia, and mislocalization of visual pigments to photoreceptor cell soma. All patient-derived cells showed reduced levels of CEP290 protein, a critical cilia transition zone component interacting with NPHP5, providing a plausible mechanism for aberrant ciliary gating and cargo transport. Disease phenotype in NPHP5-LCA retinal organoids could be rescued by adeno-associated virus (AAV)-mediated IQCB1/NPHP5 gene augmentation therapy. Our studies thus establish a human disease model and a path for treatment of NPHP5-LCA.
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Affiliation(s)
- Kamil Kruczek
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Zepeng Qu
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Emily Welby
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Hiroko Shimada
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Suja Hiriyanna
- Ocular Gene Therapy Core, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Milton A English
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Wadih M Zein
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, MD 20892, USA
| | - Anand Swaroop
- Neurobiology, Neurodegeneration & Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA.
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13
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Liu Y, Chen J, Sager R, Sasaki E, Hu H. Interactions between C8orf37 and FAM161A, Two Ciliary Proteins Essential for Photoreceptor Survival. Int J Mol Sci 2022; 23:12033. [PMID: 36233334 PMCID: PMC9570145 DOI: 10.3390/ijms231912033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/05/2022] [Accepted: 10/07/2022] [Indexed: 11/17/2022] Open
Abstract
Mutations in C8orf37 cause Bardet-Biedl syndrome (BBS), retinitis pigmentosa (RP), and cone-rod dystrophy (CRD), all manifest in photoreceptor degeneration. Little is known about which proteins C8orf37 interacts with to contribute to photoreceptor survival. To determine the proteins that potentially interact with C8orf37, we carried out a yeast two-hybrid (Y2H) screen using C8orf37 as a bait. FAM161A, a microtubule-binding protein localized at the photoreceptor cilium required for photoreceptor survival, was identified as one of the preys. Double immunofluorescence staining and proximity ligation assay (PLA) of marmoset retinal sections showed that C8orf37 was enriched and was co-localized with FAM161A at the ciliary base of photoreceptors. Epitope-tagged C8orf37 and FAM161A, expressed in HEK293 cells, were also found to be co-localized by double immunofluorescence staining and PLA. Furthermore, interaction domain mapping assays identified that the N-terminal region of C8orf37 and amino acid residues 341-517 within the PFAM UPF0564 domain of FAM161A were critical for C8orf37-FAM161A interaction. These data suggest that the two photoreceptor survival proteins, C8orf37 and FAM161A, interact with each other which may contribute to photoreceptor health.
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Affiliation(s)
- Yu Liu
- Center for Vision Research, Departments of Neuroscience and Physiology and of Ophthalmology and Visual Sciences, Upstate Medical University, Syracuse, NY 13210, USA
| | - Jinjun Chen
- Center for Vision Research, Departments of Neuroscience and Physiology and of Ophthalmology and Visual Sciences, Upstate Medical University, Syracuse, NY 13210, USA
- College of Bioscience and Biotechnology, Hunan Agricultural University, Changsha 410128, China
| | - Rachel Sager
- Center for Vision Research, Departments of Neuroscience and Physiology and of Ophthalmology and Visual Sciences, Upstate Medical University, Syracuse, NY 13210, USA
| | - Erika Sasaki
- Department of Marmoset Biology and Medicine, Central Institute for Experimental Animals, Tonomachi, Kawasaki 210-0821, Kanagawa, Japan
| | - Huaiyu Hu
- Center for Vision Research, Departments of Neuroscience and Physiology and of Ophthalmology and Visual Sciences, Upstate Medical University, Syracuse, NY 13210, USA
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14
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Senatore E, Iannucci R, Chiuso F, Delle Donne R, Rinaldi L, Feliciello A. Pathophysiology of Primary Cilia: Signaling and Proteostasis Regulation. Front Cell Dev Biol 2022; 10:833086. [PMID: 35646931 PMCID: PMC9130585 DOI: 10.3389/fcell.2022.833086] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 04/21/2022] [Indexed: 01/29/2023] Open
Abstract
Primary cilia are microtubule-based, non-motile sensory organelles present in most types of growth-arrested eukaryotic cells. They are transduction hubs that receive and transmit external signals to the cells in order to control growth, differentiation and development. Mutations of genes involved in the formation, maintenance or disassembly of ciliary structures cause a wide array of developmental genetic disorders, also known as ciliopathies. The primary cilium is formed during G1 in the cell cycle and disassembles at the G2/M transition. Following the completion of the cell division, the cilium reassembles in G1. This cycle is finely regulated at multiple levels. The ubiquitin-proteasome system (UPS) and the autophagy machinery, two main protein degradative systems in cells, play a fundamental role in cilium dynamics. Evidence indicate that UPS, autophagy and signaling pathways may act in synergy to control the ciliary homeostasis. However, the mechanisms involved and the links between these regulatory systems and cilium biogenesis, dynamics and signaling are not well defined yet. Here, we discuss the reciprocal regulation of signaling pathways and proteolytic machineries in the control of the assembly and disassembly of the primary cilium, and the impact of the derangement of these regulatory networks in human ciliopathies.
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15
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Chandra B, Tung ML, Hsu Y, Scheetz T, Sheffield VC. Retinal ciliopathies through the lens of Bardet-Biedl Syndrome: Past, present and future. Prog Retin Eye Res 2021; 89:101035. [PMID: 34929400 DOI: 10.1016/j.preteyeres.2021.101035] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 12/10/2021] [Accepted: 12/13/2021] [Indexed: 12/15/2022]
Abstract
The primary cilium is a highly specialized and evolutionary conserved organelle in eukaryotes that plays a significant role in cell signaling and trafficking. Over the past few decades tremendous progress has been made in understanding the physiology of cilia and the underlying pathomechanisms of various ciliopathies. Syndromic ciliopathies consist of a group of disorders caused by ciliary dysfunction or abnormal ciliogenesis. These disorders have multiorgan involvement in addition to retinal degeneration underscoring the ubiquitous distribution of primary cilia in different cell types. Genotype-phenotype correlation is often challenging due to the allelic heterogeneity and pleiotropy of these disorders. In this review, we discuss the clinical and genetic features of syndromic ciliopathies with a focus on Bardet-Biedl syndrome (BBS) as a representative disorder. We discuss the structure and function of primary cilia and their role in retinal photoreceptors. We describe the progress made thus far in understanding the functional and genetic characterization including expression quantitative trait locus (eQTL) analysis of BBS genes. In the future directions section, we discuss the emerging technologies, such as gene therapy, as well as anticipated challenges and their implications in therapeutic development for ciliopathies.
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Affiliation(s)
- Bharatendu Chandra
- Stead Family Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Moon Ley Tung
- Stead Family Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Ying Hsu
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, Iowa City, IA, USA
| | - Todd Scheetz
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, Iowa City, IA, USA
| | - Val C Sheffield
- Stead Family Department of Pediatrics, Division of Medical Genetics and Genomics, University of Iowa Carver College of Medicine, Iowa City, IA, USA; Department of Ophthalmology and Visual Sciences, Carver College of Medicine, Iowa City, IA, USA.
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16
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Focșa IO, Budișteanu M, Burloiu C, Khan S, Sadeghpour A, Bohîlțea LC, Davis EE, Bălgrădean M. A case of Bardet-Biedl syndrome caused by a recurrent variant in BBS12: A case report. Biomed Rep 2021; 15:103. [PMID: 34760276 PMCID: PMC8567465 DOI: 10.3892/br.2021.1479] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/29/2021] [Indexed: 12/30/2022] Open
Abstract
Bardet-Biedl syndrome (BBS) is a clinically and genetically heterogenous disorder that manifests as a result of primary cilia impairment. Cilia are present on most cell types, thus BBS is a multisystemic condition involving the majority of organ systems. The core features of the syndrome include retinal degeneration, obesity, polydactyly, cognitive impairment, renal anomalies and urogenital malformations. To date, pathogenic variants in 26 genes have been shown to be involved in the molecular basis of this rare ciliopathy. Of these causal loci, BBS12 accounts for ~8% of all cases. In this case report, an individual with BBS caused by a rare recurrent variant in BBS12 (NM_152618.3: c.1063C>T; p.Arg355*) is described and compared with others with the same DNA variant, placing this finding in the context of the current literature.
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Affiliation(s)
- Ina Ofelia Focșa
- Department of Medical Genetics, University of Medicine and Pharmacy 'Carol Davila', 021901 Bucharest, Romania
| | - Magdalena Budișteanu
- Department of Pediatric Neurology, 'Prof. Dr. Alexandru Obregia' Clinical Hospital of Psychiatry, 041914 Bucharest, Romania.,Medical Genetic Laboratory, 'Victor Babeș' National Institute of Pathology, 050096 Bucharest, Romania.,Department of Medical Genetics, Titu Maiorescu University, 040441 Bucharest, Romania
| | - Carmen Burloiu
- Department of Pediatric Neurology, 'Prof. Dr. Alexandru Obregia' Clinical Hospital of Psychiatry, 041914 Bucharest, Romania
| | - Sheraz Khan
- National Institute for Biotechnology and Genetic Engineering (NIBGE-C), Faisalabad, Pakistan Institute of Engineering and Applied Sciences, Islamabad 38000, Pakistan.,Advanced Center for Translational and Genetic Medicine, Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA
| | - Azita Sadeghpour
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC 27701, USA.,Duke Center for Applied Genomics and Precision Medicine, Duke University, Durham, NC 27708, USA
| | - Laurențiu C Bohîlțea
- Department of Medical Genetics, University of Medicine and Pharmacy 'Carol Davila', 021901 Bucharest, Romania
| | - Erica E Davis
- Advanced Center for Translational and Genetic Medicine, Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA.,Departments of Pediatrics and Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Mihaela Bălgrădean
- Department of Pediatrics and Pediatric Nephrology, Emergency Clinical Hospital for Children 'Maria Skłodowska Curie', 077120 Bucharest, Romania.,Department of Pediatrics, University of Medicine and Pharmacy 'Carol Davila', 077120 Bucharest, Romania
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17
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Potter VL, Moye AR, Robichaux MA, Wensel TG. Super-resolution microscopy reveals photoreceptor-specific subciliary location and function of ciliopathy-associated protein CEP290. JCI Insight 2021; 6:e145256. [PMID: 34520396 PMCID: PMC8564900 DOI: 10.1172/jci.insight.145256] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 09/08/2021] [Indexed: 01/19/2023] Open
Abstract
Mutations in the cilium-associated protein CEP290 cause retinal degeneration as part of multiorgan ciliopathies or as retina-specific diseases. The precise location and the functional roles of CEP290 within cilia and, specifically, the connecting cilia (CC) of photoreceptors, remain unclear. We used super-resolution fluorescence microscopy and electron microscopy to localize CEP290 in the CC and in the primary cilia of cultured cells with subdiffraction resolution and to determine effects of CEP290 deficiency in 3 mutant models. Radially, CEP290 localizes in close proximity to the microtubule doublets in the region between the doublets and the ciliary membrane. Longitudinally, it is distributed throughout the length of the CC whereas it is confined to the very base of primary cilia in human retinal pigment epithelium-1 cells. We found Y-shaped links, ciliary substructures between microtubules and membrane, throughout the length of the CC. Severe CEP290 deficiencies in mouse models did not prevent assembly of cilia or cause obvious mislocalization of ciliary components in early stages of degeneration. There were fewer cilia and no normal outer segments in the mutants, but the Y-shaped links were clearly present. These results point to photoreceptor-specific functions of CEP290 essential for CC maturation and stability following the earliest stages of ciliogenesis.
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Affiliation(s)
- Valencia L Potter
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology.,Program in Developmental Biology, Graduate School of Biomedical Sciences, and.,Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas, USA
| | - Abigail R Moye
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology
| | - Michael A Robichaux
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology.,Departments of Ophthalmology and Biochemistry, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | - Theodore G Wensel
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology
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18
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Yahalom C, Volovelsky O, Macarov M, Altalbishi A, Alsweiti Y, Schneider N, Hanany M, Khan MI, Cremers FPM, Anteby I, Banin E, Sharon D, Khateb S. SENIOR-LØKEN SYNDROME: A Case Series and Review of the Renoretinal Phenotype and Advances of Molecular Diagnosis. Retina 2021; 41:2179-2187. [PMID: 33512896 DOI: 10.1097/iae.0000000000003138] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE To report genetic and clinical findings in a case series of 10 patients from eight unrelated families diagnosed with Senior-Løken syndrome. METHODS A retrospective study of patients with Senior-Løken syndrome. Data collected included clinical findings electroretinography and ocular imaging. Genetic analysis was based on molecular inversion probes, whole-exome sequencing (WES), and Sanger sequencing. RESULTS All patients who underwent electrophysiology (8/10) had widespread photoreceptor degeneration. Genetic analysis revealed two mutations in NPHP1, two mutations in NPHP4, and two mutations in IQCB1 (NPHP5). Five of the six mutations identified in the current study were found in a single family each in our cohort. The IQCB1-p.R461* mutation has been identified in 3 families. Patients harboring mutations in IQCB1 were diagnosed with Leber congenital amaurosis, while patients with NPHP4 and NPHP1 mutations showed early and sector retinitis pigmentosa, respectively. Full-field electroretinography was extinct for 6 of 10 patients, moderately decreased for two, and unavailable for another 2 subjects. Renal involvement was evident in 7/10 patients at the time of diagnosis. Kidney function was normal (based on serum creatinine) in patients younger than 10 years. Mutations in IQCB1 were associated with high hypermetropia, whereas mutations in NPHP4 were associated with high myopia. CONCLUSION Patients presenting with infantile inherited retinal degeneration are not universally screened for renal dysfunction. Modern genetic tests can provide molecular diagnosis at an early age and therefore facilitate early diagnosis of renal disease with recommended periodic screening beyond childhood and family planning.
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Affiliation(s)
- Claudia Yahalom
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Oded Volovelsky
- Pediatric Nephrology Unit, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Michal Macarov
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Alaa Altalbishi
- St John of Jerusalem Eye Hospital Group, East Jerusalem, Israel
| | - Yahya Alsweiti
- St John of Jerusalem Eye Hospital Group, East Jerusalem, Israel
| | - Nina Schneider
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Mor Hanany
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Muhammad Imran Khan
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands ; and
| | - Frans P M Cremers
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands ; and
- Department of Human Genetics, Donders Institute for Brain, Cognition and Behavior, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Irene Anteby
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Eyal Banin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Samer Khateb
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
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19
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Bardet-Biedl syndrome proteins modulate the release of bioactive extracellular vesicles. Nat Commun 2021; 12:5671. [PMID: 34580290 PMCID: PMC8476602 DOI: 10.1038/s41467-021-25929-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 09/07/2021] [Indexed: 12/19/2022] Open
Abstract
Primary cilia are microtubule based sensory organelles important for receiving and processing cellular signals. Recent studies have shown that cilia also release extracellular vesicles (EVs). Because EVs have been shown to exert various physiological functions, these findings have the potential to alter our understanding of how primary cilia regulate specific signalling pathways. So far the focus has been on lgEVs budding directly from the ciliary membrane. An association between cilia and MVB-derived smEVs has not yet been described. We show that ciliary mutant mammalian cells demonstrate increased secretion of small EVs (smEVs) and a change in EV composition. Characterisation of smEV cargo identified signalling molecules that are differentially loaded upon ciliary dysfunction. Furthermore, we show that these smEVs are biologically active and modulate the WNT response in recipient cells. These results provide us with insights into smEV-dependent ciliary signalling mechanisms which might underly ciliopathy disease pathogenesis. Extracellular vesicles (EV) are known to be released from the primary cilium, but the role ciliary proteins play in EV biogenesis remains unexplored. Here, the authors demonstrate increased secretion of small EVs with altered cargo composition from cells with known ciliarelated mutations. Wnt related molecules made up a majority of altered cargo
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20
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Duong Phu M, Bross S, Burkhalter MD, Philipp M. Limitations and opportunities in the pharmacotherapy of ciliopathies. Pharmacol Ther 2021; 225:107841. [PMID: 33771583 DOI: 10.1016/j.pharmthera.2021.107841] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 03/11/2021] [Indexed: 01/10/2023]
Abstract
Ciliopathies are a family of rather diverse conditions, which have been grouped based on the finding of altered or dysfunctional cilia, potentially motile, small cellular antennae extending from the surface of postmitotic cells. Cilia-related disorders include embryonically arising conditions such as Joubert, Usher or Kartagener syndrome, but also afflictions with a postnatal or even adult onset phenotype, i.e. autosomal dominant polycystic kidney disease. The majority of ciliopathies are syndromic rather than affecting only a single organ due to cilia being found on almost any cell in the human body. Overall ciliopathies are considered rare diseases. Despite that, pharmacological research and the strive to help these patients has led to enormous therapeutic advances in the last decade. In this review we discuss new treatment options for certain ciliopathies, give an outlook on promising future therapeutic strategies, but also highlight the limitations in the development of therapeutic approaches of ciliopathies.
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Affiliation(s)
- Max Duong Phu
- Department of Experimental and Clinical Pharmacology and Pharmacogenomics, Section of Pharmacogenomics, Eberhard-Karls-University of Tübingen, 72074 Tübingen, Germany
| | - Stefan Bross
- Department of Experimental and Clinical Pharmacology and Pharmacogenomics, Section of Pharmacogenomics, Eberhard-Karls-University of Tübingen, 72074 Tübingen, Germany
| | - Martin D Burkhalter
- Department of Experimental and Clinical Pharmacology and Pharmacogenomics, Section of Pharmacogenomics, Eberhard-Karls-University of Tübingen, 72074 Tübingen, Germany
| | - Melanie Philipp
- Department of Experimental and Clinical Pharmacology and Pharmacogenomics, Section of Pharmacogenomics, Eberhard-Karls-University of Tübingen, 72074 Tübingen, Germany.
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21
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Aleman TS, O'Neil EC, O'Connor K, Jiang YY, Aleman IA, Bennett J, Morgan JIW, Toussaint BW. Bardet-Biedl syndrome-7 ( BBS7) shows treatment potential and a cone-rod dystrophy phenotype that recapitulates the non-human primate model. Ophthalmic Genet 2021; 42:252-265. [PMID: 33729075 DOI: 10.1080/13816810.2021.1888132] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Purpose: To provide a detailed ophthalmic phenotype of two male patients with Bardet-Biedl Syndrome (BBS) due to mutations in the BBS7 geneMethods: Two brothers ages 26 (Patient 1, P1) and 23 (P2) underwent comprehensive ophthalmic evaluations over three years. Visual function was assessed with full-field electroretinograms (ffERGs), kinetic and chromatic perimetry, multimodal imaging with spectral domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF) with short- (SW) and near-infrared (NIR) excitation lights and adaptive optics scanning light ophthalmoscopy (AOSLO).Results: Both siblings had a history of obesity and postaxial polydactyly; P2 had diagnoses of type 1 Diabetes Mellitus, Addison's disease, high-functioning autism-spectrum disorder and -12D myopia. Visual acuities were better than 20/30. Kinetic fields were moderately constricted. Cone-mediated ffERGs were undetectable, rod ERGs were ~80% of normal mean. Static perimetry showed severe central cone and rod dysfunction. Foveal to parafoveal hypoautofluorescence, most obvious on NIR-FAF, co-localized with outer segment shortening/loss and outer nuclear layer thinning by SD-OCT, and with reduced photoreceptors densities by AOSLO. A structural-functional dissociation was confirmed for cone- and rod-mediated parameters. Worsening of the above abnormalities was documented by SD-OCT and FAF in P2 at 3 years. Gene screening identified compound heterozygous mutations in BBS7 (p.Val266Glu: c.797 T > A of maternal origin; c.1781_1783delCAT, paternal) in both patients.Conclusions: BBS7-associated retinal degeneration may present as a progressive cone-rod dystrophy pattern, reminiscent of both the murine and non-human primate models of the disease. Predominantly central retinal abnormalities in both cone and rod photoreceptors showed a structural-functional dissociation, an ideal scenario for gene augmentation treatments.
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Affiliation(s)
- Tomas S Aleman
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Division of Ophthalmology of the Children's Hospital of Philadelphia, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Erin C O'Neil
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Division of Ophthalmology of the Children's Hospital of Philadelphia, Department of Ophthalmology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Keli O'Connor
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Yu You Jiang
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Isabella A Aleman
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jean Bennett
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jessica I W Morgan
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Center for Advanced Retinal and Ocular Therapeutics, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Brian W Toussaint
- Christiana Care Health System, Wilmington, Delaware, USA.,Department of Ophthalmology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, USA
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22
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Sánchez-Bellver L, Toulis V, Marfany G. On the Wrong Track: Alterations of Ciliary Transport in Inherited Retinal Dystrophies. Front Cell Dev Biol 2021; 9:623734. [PMID: 33748110 PMCID: PMC7973215 DOI: 10.3389/fcell.2021.623734] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/09/2021] [Indexed: 01/14/2023] Open
Abstract
Ciliopathies are a group of heterogeneous inherited disorders associated with dysfunction of the cilium, a ubiquitous microtubule-based organelle involved in a broad range of cellular functions. Most ciliopathies are syndromic, since several organs whose cells produce a cilium, such as the retina, cochlea or kidney, are affected by mutations in ciliary-related genes. In the retina, photoreceptor cells present a highly specialized neurosensory cilium, the outer segment, stacked with membranous disks where photoreception and phototransduction occurs. The daily renewal of the more distal disks is a unique characteristic of photoreceptor outer segments, resulting in an elevated protein demand. All components necessary for outer segment formation, maintenance and function have to be transported from the photoreceptor inner segment, where synthesis occurs, to the cilium. Therefore, efficient transport of selected proteins is critical for photoreceptor ciliogenesis and function, and any alteration in either cargo delivery to the cilium or intraciliary trafficking compromises photoreceptor survival and leads to retinal degeneration. To date, mutations in more than 100 ciliary genes have been associated with retinal dystrophies, accounting for almost 25% of these inherited rare diseases. Interestingly, not all mutations in ciliary genes that cause retinal degeneration are also involved in pleiotropic pathologies in other ciliated organs. Depending on the mutation, the same gene can cause syndromic or non-syndromic retinopathies, thus emphasizing the highly refined specialization of the photoreceptor neurosensory cilia, and raising the possibility of photoreceptor-specific molecular mechanisms underlying common ciliary functions such as ciliary transport. In this review, we will focus on ciliary transport in photoreceptor cells and discuss the molecular complexity underpinning retinal ciliopathies, with a special emphasis on ciliary genes that, when mutated, cause either syndromic or non-syndromic retinal ciliopathies.
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Affiliation(s)
- Laura Sánchez-Bellver
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
| | - Vasileios Toulis
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- CIBERER, ISCIII, Universitat de Barcelona, Barcelona, Spain
| | - Gemma Marfany
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
- CIBERER, ISCIII, Universitat de Barcelona, Barcelona, Spain
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23
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Wiegering A, Dildrop R, Vesque C, Khanna H, Schneider-Maunoury S, Gerhardt C. Rpgrip1l controls ciliary gating by ensuring the proper amount of Cep290 at the vertebrate transition zone. Mol Biol Cell 2021; 32:675-689. [PMID: 33625872 PMCID: PMC8108517 DOI: 10.1091/mbc.e20-03-0190] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A range of severe human diseases called ciliopathies is caused by the dysfunction of primary cilia. Primary cilia are cytoplasmic protrusions consisting of the basal body (BB), the axoneme, and the transition zone (TZ). The BB is a modified mother centriole from which the axoneme, the microtubule-based ciliary scaffold, is formed. At the proximal end of the axoneme, the TZ functions as the ciliary gate governing ciliary protein entry and exit. Since ciliopathies often develop due to mutations in genes encoding proteins that localize to the TZ, the understanding of the mechanisms underlying TZ function is of eminent importance. Here, we show that the ciliopathy protein Rpgrip1l governs ciliary gating by ensuring the proper amount of Cep290 at the vertebrate TZ. Further, we identified the flavonoid eupatilin as a potential agent to tackle ciliopathies caused by mutations in RPGRIP1L as it rescues ciliary gating in the absence of Rpgrip1l.
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Affiliation(s)
- Antonia Wiegering
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, 40225 Düsseldorf, Germany.,Sorbonne Université, CNRS UMR7622, INSERM U1156, Institut de Biologie Paris Seine (IBPS) - Developmental Biology Unit, 75005 Paris, France
| | - Renate Dildrop
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, 40225 Düsseldorf, Germany
| | - Christine Vesque
- Sorbonne Université, CNRS UMR7622, INSERM U1156, Institut de Biologie Paris Seine (IBPS) - Developmental Biology Unit, 75005 Paris, France
| | - Hemant Khanna
- Department of Ophthalmology and Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605
| | - Sylvie Schneider-Maunoury
- Sorbonne Université, CNRS UMR7622, INSERM U1156, Institut de Biologie Paris Seine (IBPS) - Developmental Biology Unit, 75005 Paris, France
| | - Christoph Gerhardt
- Institute for Animal Developmental and Molecular Biology, Heinrich Heine University, 40225 Düsseldorf, Germany
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24
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Role of DZIP1-CBY-FAM92 transition zone complex in the basal body to membrane attachment and ciliary budding. Biochem Soc Trans 2021; 48:1067-1075. [PMID: 32491167 DOI: 10.1042/bst20191007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 04/20/2020] [Accepted: 05/07/2020] [Indexed: 02/07/2023]
Abstract
Cilia play important signaling or motile functions in various organisms. In Human, cilia dysfunctions are responsible for a wide range of diseases, called ciliopathies. Cilia assembly is a tightly controlled process, which starts with the conversion of the centriole into a basal body, leading to the formation of the ciliary bud that protrudes inside a ciliary vesicle and/or ultimately at the cell surface. Ciliary bud formation is associated with the assembly of the transition zone (TZ), a complex architecture of proteins of the ciliary base which plays critical functions in gating proteins in and out of the ciliary compartment. Many proteins are involved in the assembly of the TZ, which shows structural and functional variations in different cell types or organisms. In this review, we discuss how a particular complex, composed of members of the DZIP1, CBY and FAM92 families of proteins, is required for the initial stages of cilia assembly leading to ciliary bud formation and how their functional hierarchy contributes to TZ assembly. Moreover, we summarize how evidences in Drosophila reveal functional differences of the DZIP1-CBY-FAM92 complex in the different ciliated tissues of this organism. Whereas it is essential for proper TZ assembly in the two types of ciliated tissues, it is involved in stable anchoring of basal bodies to the plasma membrane in male germ cells. Overall, the DZIP1-CBY-FAM92 complex reveals a molecular assembly pathway required for the initial stages of ciliary bud formation and that is conserved from Drosophila to Human.
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25
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McConnachie DJ, Stow JL, Mallett AJ. Ciliopathies and the Kidney: A Review. Am J Kidney Dis 2020; 77:410-419. [PMID: 33039432 DOI: 10.1053/j.ajkd.2020.08.012] [Citation(s) in RCA: 120] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 08/11/2020] [Indexed: 12/19/2022]
Abstract
Primary cilia are specialized sensory organelles that protrude from the apical surface of most cell types. During the past 2 decades, they have been found to play important roles in tissue development and signal transduction, with mutations in ciliary-associated proteins resulting in a group of diseases collectively known as ciliopathies. Many of these mutations manifest as renal ciliopathies, characterized by kidney dysfunction resulting from aberrant cilia or ciliary functions. This group of overlapping and genetically heterogeneous diseases includes polycystic kidney disease, nephronophthisis, and Bardet-Biedl syndrome as the main focus of this review. Renal ciliopathies are characterized by the presence of kidney cysts that develop due to uncontrolled epithelial cell proliferation, growth, and polarity, downstream of dysregulated ciliary-dependent signaling. Due to cystic-associated kidney injury and systemic inflammation, cases result in kidney failure requiring dialysis and transplantation. Of the handful of pharmacologic treatments available, none are curative. It is important to determine the molecular mechanisms that underlie the involvement of the primary cilium in cyst initiation, expansion, and progression for the development of novel and efficacious treatments. This review updates research progress in defining key genes and molecules central to ciliogenesis and renal ciliopathies.
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Affiliation(s)
- Dominique J McConnachie
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation Disease and Research, The University of Queensland, Brisbane, QLD, Australia
| | - Jennifer L Stow
- Kidney Health Service, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia
| | - Andrew J Mallett
- Institute for Molecular Bioscience (IMB) and IMB Centre for Inflammation Disease and Research, The University of Queensland, Brisbane, QLD, Australia; Kidney Health Service, Royal Brisbane and Women's Hospital, Brisbane, QLD, Australia; Faculty of Medicine, The University of Queensland, Brisbane, QLD, Australia; KidGen Collaborative, Australian Genomics Health Alliance, Melbourne, VIC, Australia.
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26
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Chen HY, Kelley RA, Li T, Swaroop A. Primary cilia biogenesis and associated retinal ciliopathies. Semin Cell Dev Biol 2020; 110:70-88. [PMID: 32747192 PMCID: PMC7855621 DOI: 10.1016/j.semcdb.2020.07.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/14/2020] [Accepted: 07/18/2020] [Indexed: 12/19/2022]
Abstract
The primary cilium is a ubiquitous microtubule-based organelle that senses external environment and modulates diverse signaling pathways in different cell types and tissues. The cilium originates from the mother centriole through a complex set of cellular events requiring hundreds of distinct components. Aberrant ciliogenesis or ciliary transport leads to a broad spectrum of clinical entities with overlapping yet highly variable phenotypes, collectively called ciliopathies, which include sensory defects and syndromic disorders with multi-organ pathologies. For efficient light detection, photoreceptors in the retina elaborate a modified cilium known as the outer segment, which is packed with membranous discs enriched for components of the phototransduction machinery. Retinopathy phenotype involves dysfunction and/or degeneration of the light sensing photoreceptors and is highly penetrant in ciliopathies. This review will discuss primary cilia biogenesis and ciliopathies, with a focus on the retina, and the role of CP110-CEP290-CC2D2A network. We will also explore how recent technologies can advance our understanding of cilia biology and discuss new paradigms for developing potential therapies of retinal ciliopathies.
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Affiliation(s)
- Holly Y Chen
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA.
| | - Ryan A Kelley
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Tiansen Li
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Anand Swaroop
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA.
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27
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Yu T, Matsuda M. Epb41l5 interacts with Iqcb1 and regulates ciliary function in zebrafish embryos. J Cell Sci 2020; 133:jcs240648. [PMID: 32501287 PMCID: PMC7338265 DOI: 10.1242/jcs.240648] [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: 10/21/2019] [Accepted: 05/13/2020] [Indexed: 11/20/2022] Open
Abstract
Erythrocyte protein band 4.1 like 5 (EPB41L5) is an adaptor protein beneath the plasma membrane that functions to control epithelial morphogenesis. Here we report a previously uncharacterized role of EPB41L5 in controlling ciliary function. We found that EPB41L5 forms a complex with IQCB1 (previously known as NPHP5), a ciliopathy protein. Overexpression of EPB41L5 reduced IQCB1 localization at the ciliary base in cultured mammalian epithelial cells. Conversely, epb41l5 knockdown increased IQCB1 localization at the ciliary base. epb41l5-deficient zebrafish embryos or embryos expressing C-terminally modified forms of Epb41l5 developed cilia with reduced motility and exhibited left-right patterning defects, an outcome of abnormal ciliary function. We observed genetic synergy between epb41l5 and iqcb1. Moreover, EPB41L5 decreased IQCB1 interaction with CEP290, another ciliopathy protein and a component of the ciliary base and centrosome. Together, these observations suggest that EPB41L5 regulates the composition of the ciliary base and centrosome through IQCB1 and CEP290.
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Affiliation(s)
- Tiffany Yu
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07302, USA
| | - Miho Matsuda
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07302, USA
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
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28
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Klink BU, Gatsogiannis C, Hofnagel O, Wittinghofer A, Raunser S. Structure of the human BBSome core complex. eLife 2020; 9:53910. [PMID: 31951201 PMCID: PMC7018512 DOI: 10.7554/elife.53910] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 01/15/2020] [Indexed: 01/09/2023] Open
Abstract
The BBSome is a heterooctameric protein complex that plays a central role in primary cilia homeostasis. Its malfunction causes the severe ciliopathy Bardet-Biedl syndrome (BBS). The complex acts as a cargo adapter that recognizes signaling proteins such as GPCRs and links them to the intraflagellar transport machinery. The underlying mechanism is poorly understood. Here we present a high-resolution cryo-EM structure of a human heterohexameric core subcomplex of the BBSome. The structure reveals the architecture of the complex in atomic detail. It explains how the subunits interact with each other and how disease-causing mutations hamper this interaction. The complex adopts a conformation that is open for binding to membrane-associated GTPase Arl6 and a large positively charged patch likely strengthens the interaction with the membrane. A prominent negatively charged cleft at the center of the complex is likely involved in binding of positively charged signaling sequences of cargo proteins.
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Affiliation(s)
- Björn Udo Klink
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Christos Gatsogiannis
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Oliver Hofnagel
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Alfred Wittinghofer
- Structural Biology Group, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
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29
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Patnaik SR, Farag A, Brücker L, Volz AK, Schneider S, Kretschmer V, May-Simera HL. Tissue-dependent differences in Bardet-Biedl syndrome gene expression. Biol Cell 2020; 112:39-52. [PMID: 31845361 DOI: 10.1111/boc.201900077] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Revised: 11/20/2019] [Accepted: 11/28/2019] [Indexed: 12/24/2022]
Abstract
BACKGROUND INFORMATION Primary cilia are highly conserved multifunctional cell organelles that extend from the cell membrane. A range of genetic disorders, collectively termed ciliopathies, is attributed to primary cilia dysfunction. The archetypical ciliopathy is the Bardet-Biedl syndrome (BBS), patients of which display virtually all symptoms associated with dysfunctional cilia. The primary cilium acts as a sensory organelle transmitting intra- and extracellular signals thereby transducing various signalling pathways facilitated by the BBS proteins. Growing evidence suggests that cilia proteins also have alternative functions in ciliary independent mechanisms, which might be contributing to disease etiology. RESULTS In an attempt to gain more insight into possible differences in organ specific roles, we examined whether relative gene expression for individual Bbs genes was constant across different tissues in mouse, in order to distinguish possible differences in organ specific roles. All tested tissues show differentially expressed Bbs transcripts with some tissues showing a more similar stoichiometric composition of transcripts than others do. However, loss of Bbs6 or Bbs8 affects expression of other Bbs transcripts in a tissue-dependent way. CONCLUSIONS AND SIGNIFICANCE Our data support the hypothesis that in some organs, BBS proteins not only function in a complex but might also have alternative functions in a ciliary independent context. This significantly alters our understanding of disease pathogenesis and development of possible treatment strategies.
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Affiliation(s)
- Sarita Rani Patnaik
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
| | - Aalaa Farag
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
| | - Lena Brücker
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
| | - Ann-Kathrin Volz
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
| | - Sandra Schneider
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
| | - Viola Kretschmer
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
| | - Helen Louise May-Simera
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, 55128, Germany
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30
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Hossain D, Barbelanne M, Tsang WY. Requirement of NPHP5 in the hierarchical assembly of basal feet associated with basal bodies of primary cilia. Cell Mol Life Sci 2020; 77:195-212. [PMID: 31177295 PMCID: PMC11104825 DOI: 10.1007/s00018-019-03181-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Revised: 05/13/2019] [Accepted: 05/31/2019] [Indexed: 11/29/2022]
Abstract
During ciliogenesis, the mother centriole transforms into a basal body competent to nucleate a cilium. The mother centriole and basal body possess sub-distal appendages (SDAs) and basal feet (BF), respectively. SDAs and BF are thought to be equivalent structures. In contrast to SDA assembly, little is known about the players involved in BF assembly and its assembly order. Furthermore, the contribution of BF to ciliogenesis is not understood. Here, we found that SDAs are distinguishable from BF and that the protein NPHP5 is a novel SDA and BF component. Remarkably, NPHP5 is specifically required for BF assembly in cells able to form basal bodies but is dispensable for SDA assembly. Determination of the hierarchical assembly reveals that NPHP5 cooperates with a subset of SDA/BF proteins to organize BF. The assembly pathway of BF is similar but not identical to that of SDA. Loss of NPHP5 or a BF protein simultaneously inhibits BF assembly and primary ciliogenesis, and these phenotypes could be rescued by manipulating the expression of certain components in the BF assembly pathway. These findings define a novel role for NPHP5 in specifically regulating BF assembly, a process which is tightly coupled to primary ciliogenesis.
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Affiliation(s)
- Delowar Hossain
- Institut de Recherches Cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
- Division of Experimental Medicine, McGill University, Montréal, QC, H3A 1A3, Canada
| | - Marine Barbelanne
- Institut de Recherches Cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada
- Département de Pathologie et Biologie Cellulaire, Faculté de Médecine, Université de Montréal, Montréal, QC, H3C 3J7, Canada
| | - William Y Tsang
- Institut de Recherches Cliniques de Montréal, 110 Avenue des Pins Ouest, Montréal, QC, H2W 1R7, Canada.
- Département de Pathologie et Biologie Cellulaire, Faculté de Médecine, Université de Montréal, Montréal, QC, H3C 3J7, Canada.
- Division of Experimental Medicine, McGill University, Montréal, QC, H3A 1A3, Canada.
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31
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Shivanna M, Anand M, Chakrabarti S, Khanna H. Ocular Ciliopathies: Genetic and Mechanistic Insights into Developing Therapies. Curr Med Chem 2019; 26:3120-3131. [PMID: 30221600 DOI: 10.2174/0929867325666180917102557] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Revised: 06/21/2018] [Accepted: 09/05/2018] [Indexed: 12/12/2022]
Abstract
Developing suitable medicines for genetic diseases requires a detailed understanding of not only the pathways that cause the disease, but also the identification of the genetic components involved in disease manifestation. This article focuses on the complexities associated with ocular ciliopathies - a class of debilitating disorders of the eye caused by ciliary dysfunction. Ciliated cell types have been identified in both the anterior and posterior segments of the eye. Photoreceptors (rods and cones) are the most studied ciliated neurons in the retina, which is located in the posterior eye. The photoreceptors contain a specialized lightsensing outer segment, or cilium. Any defects in the development or maintenance of the outer segment can result in severe retinal ciliopathies, such as retinitis pigmentosa and Leber congenital amaurosis. A role of cilia in the cell types involved in regulating aqueous fluid outflow in the anterior segment of the eye has also been recognized. Defects in these cell types are frequently associated with some forms of glaucoma. Here, we will discuss the significance of understanding the genetic heterogeneity and the pathogenesis of ocular ciliopathies to develop suitable treatment strategies for these blinding disorders.
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Affiliation(s)
- Mahesh Shivanna
- School of Optometry, Massachusetts College of Pharmacy and Health Sciences University, Worcester, MA, United States
| | - Manisha Anand
- UMASS Medical School, Worcester, MA 01605, United States
| | | | - Hemant Khanna
- UMASS Medical School, Worcester, MA 01605, United States
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32
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Kim YJ, Kim J. Therapeutic perspectives for structural and functional abnormalities of cilia. Cell Mol Life Sci 2019; 76:3695-3709. [PMID: 31147753 PMCID: PMC11105626 DOI: 10.1007/s00018-019-03158-6] [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: 02/21/2019] [Revised: 05/17/2019] [Accepted: 05/22/2019] [Indexed: 12/15/2022]
Abstract
Ciliopathies are a group of hereditary disorders that result from structural or functional abnormalities of cilia. Recent intense research efforts have uncovered the genetic bases of ciliopathies, and our understanding of the assembly and functions of cilia has been improved significantly. Although mechanism-specific therapies for ciliopathies have not yet received regulatory approval, the use of innovative therapeutic modalities such as oligonucleotide therapy, gene replacement therapy, and gene editing in addition to symptomatic treatments are expected to provide valid treatment options in the near future. Moreover, candidate chemical compounds for developing small molecule drugs to treat ciliopathies have been identified. This review introduces the key features of cilia and ciliopathies, and summarizes the advances as well as the challenges that remain with the development of therapies for treating ciliopathies.
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Affiliation(s)
- Yong Joon Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejeon, 34141, Republic of Korea
| | - Joon Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Daejeon, 34141, Republic of Korea.
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33
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Daneshmandpour Y, Darvish H, Pashazadeh F, Emamalizadeh B. Features, genetics and their correlation in Jalili syndrome: a systematic review. J Med Genet 2019; 56:358-369. [DOI: 10.1136/jmedgenet-2018-105716] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 01/02/2019] [Accepted: 01/09/2019] [Indexed: 11/03/2022]
Abstract
Jalili syndrome is a rare genetic disorder first identified by Jalili in Gaza. Amelogenesis imperfecta and cone-rode dystrophy are simultaneously seen in Jalili syndrome patients as the main and primary manifestations. Molecular analysis has revealed that theCNNM4gene is responsible for this rare syndrome. Jalili syndrome has been observed in many countries around the world, especially in the Middle East and North Africa. In the current scoping systematic review we searched electronic databases to find studies related to Jalili syndrome. In this review we summarise the reported clinical symptoms,CNNM4gene and protein structure,CNNM4mutations, attempts to reach a genotype-phenotype correlation, the functional role ofCNNM4mutations, and epidemiological aspects of Jalili syndrome. In addition, we have analysed the reported mutations in mutation effect prediction databases in order to gain a better understanding of the mutation’s outcomes.
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34
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Zhang P, Jiang W, Luo N, Zhu W, Fan L. IQ motif containing D (IQCD), a new acrosomal protein involved in the acrosome reaction and fertilisation. Reprod Fertil Dev 2019; 31:898-914. [DOI: 10.1071/rd18416] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2018] [Accepted: 12/07/2018] [Indexed: 11/23/2022] Open
Abstract
The acrosome is single, large, dense-core secretory granule overlying the nucleus of most mammalian spermatozoa. Its exocytosis, the acrosome reaction, is a crucial event during fertilisation. In this study we identified a new acrosome-associated gene, namely IQ motif containing D (IQCD), expressed nearly in multiple tissues with highest expression levels in the testis. In mouse testis, Iqcd transcript accumulated from Postnatal Day (PND) 1 to adulthood. However, expression of IQCD protein at the testicular development stage started primarily from PND 18 and increased in an age-dependent manner until plateauing in adulthood. IQCD was primarily accumulated in the acrosome area of round and elongating spermatids within seminiferous tubules of the testes during the late stage of spermiogenesis; this immunolocalisation pattern is similar in mice and humans. IQCD levels in spermatozoa were significantly lower in IVF patients with total fertilisation failure or a low fertilisation rate than in healthy men. Anti-IQCD antibody significantly inhibited the acrosome reaction and slightly reduced protein tyrosine phosphorylation levels in human spermatozoa, but specifically blocked murine IVF. IQCD interacted with mammalian homolog of C. elegans uncoordinated gene 13 (Munc13) in spermatozoa and may participate in acrosome exocytosis. In conclusion, this study identified a new acrosomal protein, namely IQCD, which is involved in fertilisation and the acrosome reaction.
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35
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Hanke-Gogokhia C, Chiodo VA, Hauswirth WW, Frederick JM, Baehr W. Rescue of cone function in cone-only Nphp5 knockout mouse model with Leber congenital amaurosis phenotype. Mol Vis 2018; 24:834-846. [PMID: 30713422 PMCID: PMC6334983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Accepted: 12/28/2018] [Indexed: 11/09/2022] Open
Abstract
Purpose Recessive mutations in the human IQCB1/NPHP5 gene are associated with Senior-Løken syndrome (SLS), a ciliopathy presenting with nephronophthisis and Leber congenital amaurosis (LCA). Nphp5-knockout mice develop LCA without nephronophthisis. Mutant rods rapidly degenerate while mutant cones survive for months. The purpose of this study was to reinitiate cone ciliogenesis in a Nphp5 -/-; Nrl -/- mouse with viral expression of full-length NPHP5 and rescue function. Methods Nphp5 -/- mice were mated with Nrl -/- mice to generate Nphp5-/-; Nrl-/- double-knockouts. Nphp5-/-; Nrl-/- mice and Nphp5+/-; Nrl-/- controls were phenotyped with confocal microscopy from postnatal day 10 (P10) until 6 months of age. Nphp5-/-; Nrl-/- mice and Nphp5+/-; Nrl-/- controls were injected at P15 with self-complementary adenoassociated virus 8 (Y733F) (AAV8(Y733F)) expressing GRK1-FL-cNPHP5. Expression of mutant NPHP5 was verified with confocal microscopy and electroretinography (ERG). Results In the Nphp5 -/- and cone-only Nphp5 -/-; Nrl -/- mice, cone outer segments did not form, but mutant cones continued to express cone pigments in the inner segments without obvious signs of cone cell death. The mutant cone outer nuclear layer (ONL) and the inner segments were stable for more than 6 months in the cone-only Nphp5 -/-; Nrl -/- retinas. Viral expression of NPHP5 initiated after eye opening showed that connecting cilia and RP1-positive axonemes were formed. Furthermore, cone pigments and other cone outer segment proteins (cone transducin and cone PDE6) were present in the nascent mutant cone outer segments, and rescued mutant cones exhibited a significant photopic b-wave (30% of Nphp5 +/-; Nrl -/- controls). Conclusions Nphp5-/-; Nrl-/- cones persistently express cone pigments in the inner segments without obvious degeneration, providing an extended duration interval for viral gene expression. Viral expression of full-length NPHP5 initiates ciliogenesis between P15 and P60, and mutant cones are, in part, functional, encouraging future retina gene replacement therapy.
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Affiliation(s)
- Christin Hanke-Gogokhia
- Department of Ophthalmology, John A. Moran Eye Center, University of Utah Health Science Center, Salt Lake City, UT
| | - Vince A. Chiodo
- Department of Ophthalmology, University of Florida, Gainesville, FL
| | | | - Jeanne M. Frederick
- Department of Ophthalmology, John A. Moran Eye Center, University of Utah Health Science Center, Salt Lake City, UT
| | - Wolfgang Baehr
- Department of Ophthalmology, John A. Moran Eye Center, University of Utah Health Science Center, Salt Lake City, UT,Department of Neurobiology and Anatomy, University of Utah Health Science Center, Salt Lake City, UT,Department of Biology, University of Utah, Salt Lake City, UT
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Baehr W, Hanke-Gogokhia C, Sharif A, Reed M, Dahl T, Frederick JM, Ying G. Insights into photoreceptor ciliogenesis revealed by animal models. Prog Retin Eye Res 2018; 71:26-56. [PMID: 30590118 DOI: 10.1016/j.preteyeres.2018.12.004] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 12/10/2018] [Accepted: 12/18/2018] [Indexed: 12/11/2022]
Abstract
Photoreceptors are polarized neurons, with very specific subcellular compartmentalization and unique requirements for protein expression and trafficking. Each photoreceptor contains an outer segment, the site of photon capture that initiates vision, an inner segment that houses the biosynthetic machinery and a synaptic terminal for signal transmission to downstream neurons. Outer segments and inner segments are connected by a connecting cilium (CC), the equivalent of a transition zone (TZ) of primary cilia. The connecting cilium is part of the basal body/axoneme backbone that stabilizes the outer segment. This report will update the reader on late developments in photoreceptor ciliogenesis and transition zone formation, specifically in mouse photoreceptors, focusing on early events in photoreceptor ciliogenesis. The connecting cilium, an elongated and narrow structure through which all outer segment proteins and membrane components must traffic, functions as a gate that controls access to the outer segment. Here we will review genes and their protein products essential for basal body maturation and for CC/TZ genesis, sorted by phenotype. Emphasis is given to naturally occurring mouse mutants and gene knockouts that interfere with CC/TZ formation and ciliogenesis.
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Affiliation(s)
- Wolfgang Baehr
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA.
| | - Christin Hanke-Gogokhia
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Ali Sharif
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Michelle Reed
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Tiffanie Dahl
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Jeanne M Frederick
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
| | - Guoxin Ying
- Department of Ophthalmology and Visual Sciences, University of Utah Health Sciences, Salt Lake City, UT, 84132, USA
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Kilander MBC, Wang CH, Chang CH, Nestor JE, Herold K, Tsai JW, Nestor MW, Lin YC. A rare human CEP290 variant disrupts the molecular integrity of the primary cilium and impairs Sonic Hedgehog machinery. Sci Rep 2018; 8:17335. [PMID: 30478281 PMCID: PMC6255789 DOI: 10.1038/s41598-018-35614-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 11/07/2018] [Indexed: 12/25/2022] Open
Abstract
The primary cilium is a microtubule-enriched cell-communication organelle that participates in mechanisms controlling tissue development and maintenance, including cerebellar architecture. Centrosomal protein of 290 kDa (CEP290) is a protein important for centrosomal function and ciliogenesis. Mutations in CEP290 have been linked to a group of multi-organ disorders - termed ciliopathies. The neurophysiological deficits observed in ciliopathies are sometimes associated with the progression of autistic traits. Here, the cellular function of two rare variants of CEP290 identified from recent exome sequencing of autistic individuals are investigated. Cells expressing Cep290 carrying the missense mutation R1747Q in mouse exhibited a defective Sonic hedgehog (Shh) signalling response, mislocalisation of the Shh receptor Smoothened (Smo), and dysregulation of ciliary protein mobility, which ultimately disrupted the proliferation of cerebellar granule progenitors (CGPs). This data was furthermore corroborated in an autism patient-derived iPSC line harbouring the R1746Q rare CEP290 variant. Evidence from this study suggests that the R1746Q mutation interferes with the function of CEP290 to maintain the ciliary diffusion barrier and disrupts the integrity of the molecular composition in the primary cilium, which may contribute to alterations in neuroarchitecture.
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Affiliation(s)
| | - Chun-Hung Wang
- Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, 112, Taiwan
| | - Chia-Hsiang Chang
- Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, 112, Taiwan
- Taiwan International Graduate Program (TIGP) in Molecular Medicine, National Yang-Ming University and Academia Sinica, Taipei, Taiwan
| | - Jonathan E Nestor
- Program in Neuroscience, Hussman Institute for Autism, Baltimore, MD, 21201, USA
| | - Kevin Herold
- Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
| | - Jin-Wu Tsai
- Institute of Brain Science, School of Medicine, National Yang-Ming University, Taipei, 112, Taiwan
- Brain Research Center (BRC), and Biophotonics and Molecular Imaging Research Center (BMIRC), National Yang-Ming University, Taipei, 112, Taiwan
| | - Michael W Nestor
- Program in Neuroscience, Hussman Institute for Autism, Baltimore, MD, 21201, USA
| | - Yu-Chih Lin
- Program in Neuroscience, Hussman Institute for Autism, Baltimore, MD, 21201, USA.
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Hossain D, Tsang WY. The role of ubiquitination in the regulation of primary cilia assembly and disassembly. Semin Cell Dev Biol 2018; 93:145-152. [PMID: 30213760 DOI: 10.1016/j.semcdb.2018.09.005] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Revised: 09/04/2018] [Accepted: 09/05/2018] [Indexed: 01/02/2023]
Abstract
The primary cilium is a cellular antenna found on the surface of many eukaryotic cells, whose main role is to sense and transduce signals that regulate growth, development, and differentiation. Although once believed to be a vestigial organelle without important function, it has become clear that defects in primary cilium are responsible for a wide variety of genetic diseases affecting many organs and tissues, including the brain, eyes, heart, kidneys, liver, and pancreas. The primary cilium is mainly present in quiescent and differentiated cells, and controls must exist to ensure that this organelle is assembled or disassembled at the right time. Although many protein components required for building the cilium have been identified, mechanistic details of how these proteins are spatially and temporally regulated and how these regulations are connected to external cues are beginning to emerge. This review article highlights the role of ubiquitination and in particular, E3 ubiquitin ligases and deubiquitinases, in the control of primary cilia assembly and disassembly.
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Affiliation(s)
- Delowar Hossain
- Institut de recherches cliniques de Montréal, Montreal, Quebec, H2W 1R7, Canada; Division of Experimental Medicine, McGill University, Montreal, Quebec, H4A 3J1, Canada
| | - William Y Tsang
- Institut de recherches cliniques de Montréal, Montreal, Quebec, H2W 1R7, Canada; Division of Experimental Medicine, McGill University, Montreal, Quebec, H4A 3J1, Canada; Department of Pathology and Cell Biology, Université de Montréal, Montreal, Quebec, H3C 3J7, Canada.
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Kim YJ, Kim S, Jung Y, Jung E, Kwon HJ, Kim J. Eupatilin rescues ciliary transition zone defects to ameliorate ciliopathy-related phenotypes. J Clin Invest 2018; 128:3642-3648. [PMID: 30035750 DOI: 10.1172/jci99232] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Accepted: 05/31/2018] [Indexed: 12/21/2022] Open
Abstract
Ciliopathies are clinically overlapping genetic disorders involving structural and functional abnormalities of cilia. Currently, there are no small-molecule drugs available to treat ciliary defects in ciliopathies. Our phenotype-based screen identified the flavonoid eupatilin and its analogs as lead compounds for developing ciliopathy medication. CEP290, a gene mutated in several ciliopathies, encodes a protein that forms a complex with NPHP5 to support the function of the ciliary transition zone. Eupatilin relieved ciliogenesis and ciliary receptor delivery defects resulting from deletion of CEP290. In rd16 mice harboring a blinding Cep290 in-frame deletion, eupatilin treatment improved both opsin transport to the photoreceptor outer segment and electrophysiological responses of the retina to light stimulation. The rescue effect was due to eupatilin-mediated inhibition of calmodulin binding to NPHP5, which promoted NPHP5 recruitment to the ciliary base. Our results suggest that deficiency of a ciliopathy protein could be mitigated by small-molecule compounds that target other ciliary components that interact with the ciliopathy protein.
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Affiliation(s)
- Yong Joon Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Sungsoo Kim
- Chemical Genomics Global Research Laboratory, Department of Biotechnology, Yonsei University, Seoul, South Korea
| | - Yooju Jung
- Chemical Genomics Global Research Laboratory, Department of Biotechnology, Yonsei University, Seoul, South Korea
| | - Eunji Jung
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
| | - Ho Jeong Kwon
- Chemical Genomics Global Research Laboratory, Department of Biotechnology, Yonsei University, Seoul, South Korea
| | - Joon Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, South Korea
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Hossain D, Ferreira Barbosa JA, Cohen ÉA, Tsang WY. HIV-1 Vpr hijacks EDD-DYRK2-DDB1 DCAF1 to disrupt centrosome homeostasis. J Biol Chem 2018; 293:9448-9460. [PMID: 29724823 PMCID: PMC6005440 DOI: 10.1074/jbc.ra117.001444] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 04/17/2018] [Indexed: 11/06/2022] Open
Abstract
Viruses exploit the host cell machinery for their own profit. To evade innate immune sensing and promote viral replication, HIV type 1 (HIV-1) subverts DNA repair regulatory proteins and induces G2/M arrest. The preintegration complex of HIV-1 is known to traffic along microtubules and accumulate near the microtubule-organizing center. The centrosome is the major microtubule-organizing center in most eukaryotic cells, but precisely how HIV-1 impinges on centrosome biology remains poorly understood. We report here that the HIV-1 accessory protein viral protein R (Vpr) localized to the centrosome through binding to DCAF1, forming a complex with the ubiquitin ligase EDD-DYRK2-DDB1DCAF1 and Cep78, a resident centrosomal protein previously shown to inhibit EDD-DYRK2-DDB1DCAF1 Vpr did not affect ubiquitination of Cep78. Rather, it enhanced ubiquitination of an EDD-DYRK2-DDB1DCAF1 substrate, CP110, leading to its degradation, an effect that could be overcome by Cep78 expression. The down-regulation of CP110 and elongation of centrioles provoked by Vpr were independent of G2/M arrest. Infection of T lymphocytes with HIV-1, but not with HIV-1 lacking Vpr, promoted CP110 degradation and centriole elongation. Elongated centrioles recruited more γ-tubulin to the centrosome, resulting in increased microtubule nucleation. Our results suggest that Vpr is targeted to the centrosome where it hijacks a ubiquitin ligase, disrupting organelle homeostasis, which may contribute to HIV-1 pathogenesis.
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Affiliation(s)
- Delowar Hossain
- From the Institut de recherches cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada
- the Division of Experimental Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
| | | | - Éric A Cohen
- From the Institut de recherches cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada
- the Division of Experimental Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
- the Department of Microbiology, Infectiology, and Immunology, Université de Montréal, Montreal, Quebec H3C 3J7, Canada, and
| | - William Y Tsang
- From the Institut de recherches cliniques de Montréal, Montreal, Quebec H2W 1R7, Canada,
- the Division of Experimental Medicine, McGill University, Montreal, Quebec H4A 3J1, Canada
- the Department of Pathology and Cell Biology, Université de Montréal, Montreal, Quebec H3C 3J7, Canada
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41
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Ye F, Nager AR, Nachury MV. BBSome trains remove activated GPCRs from cilia by enabling passage through the transition zone. J Cell Biol 2018; 217:1847-1868. [PMID: 29483145 PMCID: PMC5940304 DOI: 10.1083/jcb.201709041] [Citation(s) in RCA: 167] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2017] [Revised: 12/27/2017] [Accepted: 01/29/2018] [Indexed: 02/08/2023] Open
Abstract
A diffusion barrier at the transition zone enables the compartmentalization of signaling molecules by cilia. The BBSome and the small guanosine triphosphatase Arl6, which triggers BBSome coat polymerization, are required for the exit of activated signaling receptors from cilia, but how diffusion barriers are crossed when membrane proteins exit cilia remains to be determined. In this study, we found that activation of the ciliary G protein-coupled receptors (GPCRs) Smoothened and SSTR3 drove the Arl6-dependent assembly of large, highly processive, and cargo-laden retrograde BBSome trains. Single-molecule imaging revealed that the assembly of BBSome trains enables the lateral transport of ciliary GPCRs across the transition zone. However, the removal of activated GPCRs from cilia was inefficient because a second periciliary diffusion barrier was infrequently crossed. We conclude that exit from cilia is a two-step process in which BBSome/Arl6 trains first move activated GPCRs through the transition zone before a periciliary barrier can be crossed.
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Affiliation(s)
- Fan Ye
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA
| | - Andrew R Nager
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA
| | - Maxence V Nachury
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA
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Garcia G, Raleigh DR, Reiter JF. How the Ciliary Membrane Is Organized Inside-Out to Communicate Outside-In. Curr Biol 2018; 28:R421-R434. [PMID: 29689227 PMCID: PMC6434934 DOI: 10.1016/j.cub.2018.03.010] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Cilia, organelles that move to execute functions like fertilization and signal to execute functions like photoreception and embryonic patterning, are composed of a core of nine-fold doublet microtubules overlain by a membrane. Distinct types of cilia display distinct membrane morphologies, ranging from simple domed cylinders to the highly ornate invaginations and membrane disks of photoreceptor outer segments. Critical for the ability of cilia to signal, both the protein and the lipid compositions of ciliary membranes are different from those of other cellular membranes. This specialization presents a unique challenge for the cell as, unlike membrane-bounded organelles, the ciliary membrane is contiguous with the surrounding plasma membrane. This distinct ciliary membrane is generated in concert with multiple membrane remodeling events that comprise the process of ciliogenesis. Once the cilium is formed, control of ciliary membrane composition relies on discrete molecular machines, including a barrier to membrane proteins entering the cilium at a specialized region of the base of the cilium called the transition zone and a trafficking adaptor that controls G protein-coupled receptor (GPCR) localization to the cilium called the BBSome. The ciliary membrane can be further remodeled by the removal of membrane proteins by the release of ciliary extracellular vesicles that may function in intercellular communication, removal of unneeded proteins or ciliary disassembly. Here, we review the structures and transport mechanisms that control ciliary membrane composition, and discuss how membrane specialization enables the cilium to function as the antenna of the cell.
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Affiliation(s)
- Galo Garcia
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA
| | - David R Raleigh
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA; Department of Radiation Oncology, University of California, San Francisco, CA 94143, USA; Department of Neurological Surgery, University of California, San Francisco, CA 94143, USA
| | - Jeremy F Reiter
- Department of Biochemistry and Biophysics, Cardiovascular Research Institute, University of California, San Francisco, CA 94158, USA.
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Uyhazi KE, Binenbaum G, Carducci N, Zackai EH, Aleman TS. Early photoreceptor outer segment loss and retinoschisis in Cohen syndrome. Ophthalmic Genet 2018; 39:399-404. [DOI: 10.1080/13816810.2018.1459735] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Katherine E. Uyhazi
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Gil Binenbaum
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Division of Ophthalmology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Nicholas Carducci
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Elaine H. Zackai
- Division of Human Genetics, The Children’s Hospital of Philadelphia, Philadelphia, PA, USA
| | - Tomas S. Aleman
- Scheie Eye Institute at the Perelman Center for Advanced Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Division of Ophthalmology, Children’s Hospital of Philadelphia, Philadelphia, PA, USA
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Abstract
Cilia are microtubule-based organelles extending from a basal body at the surface of eukaryotic cells. Cilia regulate cell and fluid motility, sensation and developmental signaling, and ciliary defects cause human diseases (ciliopathies) affecting the formation and function of many tissues and organs. Over the past decade, various Rab and Rab-like membrane trafficking proteins have been shown to regulate cilia-related processes such as basal body maturation, ciliary axoneme extension, intraflagellar transport and ciliary signaling. In this review, we provide a comprehensive overview of Rab protein ciliary associations, drawing on findings from multiple model systems, including mammalian cell culture, mice, zebrafish, C. elegans, trypanosomes, and green algae. We also discuss several emerging mechanistic themes related to ciliary Rab cascades and functional redundancy.
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Affiliation(s)
- Oliver E Blacque
- a School of Biomolecular and Biomedical Science , University College Dublin , Belfield, Dublin , Ireland
| | - Noemie Scheidel
- a School of Biomolecular and Biomedical Science , University College Dublin , Belfield, Dublin , Ireland
| | - Stefanie Kuhns
- a School of Biomolecular and Biomedical Science , University College Dublin , Belfield, Dublin , Ireland
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Li S, Xi Q, Zhang X, Yu D, Li L, Jiang Z, Chen Q, Wang QK, Traboulsi EI. Identification of a mutation in CNNM4 by whole exome sequencing in an Amish family and functional link between CNNM4 and IQCB1. Mol Genet Genomics 2018; 293:699-710. [PMID: 29322253 DOI: 10.1007/s00438-018-1417-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 01/06/2018] [Indexed: 12/15/2022]
Abstract
We investigated an Amish family in which three siblings presented with an early-onset childhood retinal dystrophy inherited in an autosomal recessive fashion. Genome-wide linkage analysis identified significant linkage to marker D2S2216 on 2q11 with a two-point LOD score of 1.95 and a multi-point LOD score of 3.76. Whole exome sequencing was then performed for the three affected individuals and identified a homozygous nonsense mutation (c.C1813T, p.R605X) in the cyclin and CBS domain divalent metal cation transport mediator 4 (CNNM4) gene located within the 2p14-2q14 Jalili syndrome locus. The initial assessment and collection of the family were performed before the clinical delineation of Jalili syndrome. Another assessment was made after the discovery of the responsible gene and the dental abnormalities characteristic of Jalili syndrome were retrospectively identified. The p.R605X mutation represents the first probable founder mutation of Jalili syndrome identified in the Amish community. The molecular mechanism underlying Jalili syndrome is unknown. Here we show that CNNM4 interacts with IQCB1, which causes Leber congenital amaurosis (LCA) when mutated. A truncated CNNM4 protein starting at R605 significantly increased the rate of apoptosis, and significantly increased the interaction between CNNM4 and IQCB1. Mutation p.R605X may cause Jalili syndrome by a nonsense-mediated decay mechanism, affecting the function of IQCB1 and apoptosis, or both. Our data, for the first time, functionally link Jalili syndrome gene CNNM4 to LCA gene IQCB1, providing important insights into the molecular pathogenic mechanism of retinal dystrophy in Jalili syndrome.
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Affiliation(s)
- Sisi Li
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Center for Human Genome Research and Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Quansheng Xi
- Department of Molecular Cardiology, Center for Cardiovascular Genetics, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - Xiaoyu Zhang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Center for Human Genome Research and Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Dong Yu
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Center for Human Genome Research and Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Lin Li
- Department of Molecular Cardiology, Center for Cardiovascular Genetics, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
| | - Zhenyang Jiang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Center for Human Genome Research and Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Qiuyun Chen
- Department of Molecular Cardiology, Center for Cardiovascular Genetics, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Cleveland, USA
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44195, USA
| | - Qing K Wang
- Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Center for Human Genome Research and Cardio-X Institute, Huazhong University of Science and Technology, Wuhan, 430074, China.
- Department of Molecular Cardiology, Center for Cardiovascular Genetics, Cleveland Clinic Lerner Research Institute, Cleveland, OH, 44195, USA.
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Cleveland, USA.
- Department of Genetics and Genome Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, 44195, USA.
| | - Elias I Traboulsi
- Center for Genetic Eye Diseases, Cleveland Clinic Cole Eye Institute, Cleveland, OH, 44195, USA.
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Kalsner L, Twachtman-Bassett J, Tokarski K, Stanley C, Dumont-Mathieu T, Cotney J, Chamberlain S. Genetic testing including targeted gene panel in a diverse clinical population of children with autism spectrum disorder: Findings and implications. Mol Genet Genomic Med 2017; 6:171-185. [PMID: 29271092 PMCID: PMC5902398 DOI: 10.1002/mgg3.354] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Revised: 10/20/2017] [Accepted: 10/24/2017] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Genetic testing of children with autism spectrum disorder (ASD) is now standard in the clinical setting, with American College of Medical Genetics and Genomics (ACMGG) guidelines recommending microarray for all children, fragile X testing for boys and additional gene sequencing, including PTEN and MECP2, in appropriate patients. Increasingly, testing utilizing high throughput sequencing, including gene panels and whole exome sequencing, are offered as well. METHODS We performed genetic testing including microarray, fragile X testing and targeted gene panel, consistently sequencing 161 genes associated with ASD risk, in a clinical population of 100 well characterized children with ASD. Frequency of rare variants identified in individual genes was compared with that reported in the Exome Aggregation Consortium (ExAC) database. RESULTS We did not diagnose any conditions with complete penetrance for ASD; however, copy number variants believed to contribute to ASD risk were identified in 12%. Eleven children were found to have likely pathogenic variants on gene panel, yet, after careful analysis, none was considered likely causative of disease. KIRREL3 variants were identified in 6.7% of children compared to 2% in ExAC, suggesting a potential role for KIRREL3 variants in ASD risk. Children with KIRREL3 variants more often had minor facial dysmorphism and intellectual disability. We also observed an increase in rare variants in TSC2. However, analysis of variant data from the Simons Simplex Collection indicated that rare variants in TSC2 occur more commonly in specific racial/ethnic groups, which are more prevalent in our population than in the ExAC database. CONCLUSION The yield of genetic testing including microarray, fragile X (boys) and targeted gene panel was 12%. Gene panel did not increase diagnostic yield; however, we found an increase in rare variants in KIRREL3. Our findings reinforce the need for racial/ethnic diversity in large-scale genomic databases used to identify variants that contribute to disease risk.
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Affiliation(s)
- Louisa Kalsner
- Connecticut Children's Medical Center, Farmington, CT, USA.,University of Connecticut School of Medicine, Farmington, CT, USA
| | | | - Kristin Tokarski
- University of Connecticut School of Medicine, Farmington, CT, USA
| | | | - Thyde Dumont-Mathieu
- Connecticut Children's Medical Center, Farmington, CT, USA.,University of Connecticut School of Medicine, Farmington, CT, USA
| | - Justin Cotney
- University of Connecticut School of Medicine, Farmington, CT, USA
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47
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Klink BU, Zent E, Juneja P, Kuhlee A, Raunser S, Wittinghofer A. A recombinant BBSome core complex and how it interacts with ciliary cargo. eLife 2017; 6. [PMID: 29168691 PMCID: PMC5700813 DOI: 10.7554/elife.27434] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 11/03/2017] [Indexed: 01/07/2023] Open
Abstract
Cilia are small, antenna-like structures on the surface of eukaryotic cells that harbor a unique set of sensory proteins, including GPCRs and other membrane proteins. The transport of these proteins involves the BBSome, an eight-membered protein complex that is recruited to ciliary membranes by the G-protein Arl6. BBSome malfunction leads to Bardet-Biedl syndrome, a ciliopathy with severe consequences. Short ciliary targeting sequences (CTS) have been identified that trigger the transport of ciliary proteins. However, mechanistic studies that relate ciliary targeting to BBSome binding are missing. Here we used heterologously expressed BBSome subcomplexes to analyze the complex architecture and to investigate the binding of GPCRs and other receptors to the BBSome. A stable heterohexameric complex was identified that binds to GPCRs with interactions that only partially overlap with previously described CTS, indicating a more complex recognition than anticipated. Arl6•GTP does not affect these interactions, suggesting no direct involvement in cargo loading/unloading.
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Affiliation(s)
- Björn Udo Klink
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.,Structural Biology Group, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Eldar Zent
- Structural Biology Group, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Puneet Juneja
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Anne Kuhlee
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Alfred Wittinghofer
- Structural Biology Group, Max Planck Institute of Molecular Physiology, Dortmund, Germany
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48
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Abstract
Cilia are microtubule-based organelles extending from a basal body at the surface of eukaryotic cells. Cilia regulate cell and fluid motility, sensation and developmental signaling, and ciliary defects cause human diseases (ciliopathies) affecting the formation and function of many tissues and organs. Over the past decade, various Rab and Rab-like membrane trafficking proteins have been shown to regulate cilia-related processes such as basal body maturation, ciliary axoneme extension, intraflagellar transport and ciliary signaling. In this review, we provide a comprehensive overview of Rab protein ciliary associations, drawing on findings from multiple model systems, including mammalian cell culture, mice, zebrafish, C. elegans, trypanosomes, and green algae. We also discuss several emerging mechanistic themes related to ciliary Rab cascades and functional redundancy.
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Affiliation(s)
- Oliver E Blacque
- a School of Biomolecular and Biomedical Science , University College Dublin , Belfield, Dublin , Ireland
| | - Noemie Scheidel
- a School of Biomolecular and Biomedical Science , University College Dublin , Belfield, Dublin , Ireland
| | - Stefanie Kuhns
- a School of Biomolecular and Biomedical Science , University College Dublin , Belfield, Dublin , Ireland
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49
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Weihbrecht K, Goar WA, Pak T, Garrison JE, DeLuca AP, Stone EM, Scheetz TE, Sheffield VC. Keeping an Eye on Bardet-Biedl Syndrome: A Comprehensive Review of the Role of Bardet-Biedl Syndrome Genes in the Eye. MEDICAL RESEARCH ARCHIVES 2017; 5. [PMID: 29457131 DOI: 10.18103/mra.v5i9.1526] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Upwards of 90% of individuals with Bardet-Biedl syndrome (BBS) display rod-cone dystrophy with early macular involvement. BBS is an autosomal recessive, genetically heterogeneous, pleiotropic ciliopathy for which 21 causative genes have been discovered to date. In addition to retinal degeneration, the cardinal features of BBS include obesity, cognitive impairment, renal anomalies, polydactyly, and hypogonadism. Here, we review the genes, proteins, and protein complexes involved in BBS and the BBS model organisms available for the study of retinal degeneration. We include comprehensive lists for all known BBS genes, their known phenotypes, and the model organisms available. We also review the molecular mechanisms believed to lead to retinal degeneration. We provide an overview of the mode of inheritance and describe the relationships between BBS genes and Joubert syndrome, Leber Congenital Amaurosis, Senior-Løken syndrome, and non-syndromic retinitis pigmentosa. Finally, we propose ways that new advances in technology will allow us to better understand the role of different BBS genes in retinal formation and function.
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Affiliation(s)
- Katie Weihbrecht
- Department of Pediatrics, University of Iowa; Iowa City, IA 52242, USA.,Department of Ophthalmology and Visual Sciences, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Wesley A Goar
- Department of Pediatrics, University of Iowa; Iowa City, IA 52242, USA.,Department of Ophthalmology and Visual Sciences, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Thomas Pak
- Department of Pediatrics, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Janelle E Garrison
- Department of Pediatrics, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Adam P DeLuca
- Department of Ophthalmology and Visual Sciences, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Edwin M Stone
- Department of Ophthalmology and Visual Sciences, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Todd E Scheetz
- Department of Ophthalmology and Visual Sciences, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
| | - Val C Sheffield
- Department of Pediatrics, University of Iowa; Iowa City, IA 52242, USA.,Department of Ophthalmology and Visual Sciences, University of Iowa; Iowa City, IA 52242, USA.,Stephen A. Wynn Institute for Vision Research, University of Iowa; Iowa City, IA 52242, USA
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50
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Liu Y, Nie H, Liu C, Zhai X, Sang Q, Wang Y, Shi D, Wang L, Xu Z. Angulin proteins ILDR1 and ILDR2 regulate alternative pre-mRNA splicing through binding to splicing factors TRA2A, TRA2B, or SRSF1. Sci Rep 2017; 7:7466. [PMID: 28785060 PMCID: PMC5547134 DOI: 10.1038/s41598-017-07530-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 06/29/2017] [Indexed: 01/08/2023] Open
Abstract
Angulin proteins are a group of evolutionally conserved type I transmembrane proteins that contain an extracellular Ig-like domain. In mammals, three angulin proteins have been identified, namely immunoglobulin-like domain containing receptor 1 (ILDR1), immunoglobulin-like domain containing receptor 2 (ILDR2), and lipolysis-stimulated lipoprotein receptor (LSR). All three proteins have been shown to localize at tight junctions (TJs) and are important for TJ formation. Mutations in ILDR1 gene have been shown to cause non-syndromic hearing loss (NSHL). In the present work, we show that ILDR1 binds to splicing factors TRA2A, TRA2B, and SRSF1, and translocates into the nuclei when the splicing factors are present. Moreover, ILDR1 affects alternative splicing of Tubulin delta 1 (TUBD1), IQ motif containing B1 (IQCB1), and Protocadherin 19 (Pcdh19). Further investigation show that ILDR2, but not LSR, also binds to the splicing factors and regulates alternative splicing. When endogenous ILDR1 and ILDR2 expression is knockdown with siRNAs in cultured cells, alternative splicing of TUBD1 and IQCB1 is affected. In conclusion, we show here that angulin proteins ILDR1 and ILDR2 are involved in alternative pre-mRNA splicing via binding to splicing factors TRA2A, TRA2B, or SRSF1.
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Affiliation(s)
- Yueyue Liu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, Shandong University School of Life Sciences, Jinan, Shandong, 250100, China
| | - Hongyun Nie
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, Shandong University School of Life Sciences, Jinan, Shandong, 250100, China
| | - Chengcheng Liu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, Shandong University School of Life Sciences, Jinan, Shandong, 250100, China
| | - Xiaoyan Zhai
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, Shandong University School of Life Sciences, Jinan, Shandong, 250100, China
| | - Qing Sang
- State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, 200032, China
| | - Yanfei Wang
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, Shandong University School of Life Sciences, Jinan, Shandong, 250100, China
| | - Deli Shi
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, Shandong University School of Life Sciences, Jinan, Shandong, 250100, China.,Laboratoire de Biologie du Développement, Institut de Biologie Paris-Seine, Sorbonne Universités, Paris, France
| | - Lei Wang
- State Key Laboratory of Genetic Engineering and MOE Key Laboratory of Contemporary Anthropology, School of Life Sciences, Fudan University, Shanghai, 200032, China.
| | - Zhigang Xu
- Shandong Provincial Key Laboratory of Animal Cells and Developmental Biology, Shandong University School of Life Sciences, Jinan, Shandong, 250100, China.
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