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Jaiswal A, Boring A, Mukherjee A, Avidor-Reiss T. Fly Fam161 is an essential centriole and cilium transition zone protein with unique and diverse cell type-specific localizations. Open Biol 2024; 14:240036. [PMID: 39255847 DOI: 10.1098/rsob.240036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2024] [Revised: 05/17/2024] [Accepted: 07/15/2024] [Indexed: 09/12/2024] Open
Abstract
Family with sequence similarity 161 (Fam161) is an ancient family of microtubule-binding proteins located at the centriole and cilium transition zone (TZ) lumen that exhibit rapid evolution in mice. However, their adaptive role is unclear. Here, we used flies to gain insight into their cell type-specific adaptations. Fam161 is the sole orthologue of FAM161A and FAM161B found in flies. Mutating Fam161 results in reduced male reproduction and abnormal geotaxis behaviour. Fam161 localizes to sensory neuron centrioles and their specialized TZ (the connecting cilium) in a cell type-specific manner, sometimes labelling only the centrioles, sometimes labelling the centrioles and cilium TZ and sometimes labelling the TZ with varying lengths that are longer than other TZ proteins, defining a new ciliary compartment, the extra distal TZ. These findings suggest that Fam161 is an essential centriole and TZ protein with a unique cell type-specific localization in fruit flies that can produce cell type-specific adaptations.
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Affiliation(s)
- Ankit Jaiswal
- Department of Biological Sciences, University of Toledo , Toledo, OH 43606, USA
| | - Andrew Boring
- Department of Biological Sciences, University of Toledo , Toledo, OH 43606, USA
- Department of Urology, College of Medicine and Life Sciences, University of Toledo , Toledo, OH 43614, USA
| | - Avik Mukherjee
- Department of Biological Sciences, University of Toledo , Toledo, OH 43606, USA
| | - Tomer Avidor-Reiss
- Department of Biological Sciences, University of Toledo , Toledo, OH 43606, USA
- Department of Urology, College of Medicine and Life Sciences, University of Toledo , Toledo, OH 43614, USA
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2
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Arsenijevic Y, Chang N, Mercey O, El Fersioui Y, Koskiniemi-Kuendig H, Joubert C, Bemelmans AP, Rivolta C, Banin E, Sharon D, Guichard P, Hamel V, Kostic C. Fine-tuning FAM161A gene augmentation therapy to restore retinal function. EMBO Mol Med 2024; 16:805-822. [PMID: 38504136 PMCID: PMC11018783 DOI: 10.1038/s44321-024-00053-x] [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: 01/10/2024] [Revised: 02/28/2024] [Accepted: 02/28/2024] [Indexed: 03/21/2024] Open
Abstract
For 15 years, gene therapy has been viewed as a beacon of hope for inherited retinal diseases. Many preclinical investigations have centered around vectors with maximal gene expression capabilities, yet despite efficient gene transfer, minimal physiological improvements have been observed in various ciliopathies. Retinitis pigmentosa-type 28 (RP28) is the consequence of bi-allelic null mutations in the FAM161A, an essential protein for the structure of the photoreceptor connecting cilium (CC). In its absence, cilia become disorganized, leading to outer segment collapses and vision impairment. Within the human retina, FAM161A has two isoforms: the long one with exon 4, and the short one without it. To restore CC in Fam161a-deficient mice shortly after the onset of cilium disorganization, we compared AAV vectors with varying promoter activities, doses, and human isoforms. While all vectors improved cell survival, only the combination of both isoforms using the weak FCBR1-F0.4 promoter enabled precise FAM161A expression in the CC and enhanced retinal function. Our investigation into FAM161A gene replacement for RP28 emphasizes the importance of precise therapeutic gene regulation, appropriate vector dosing, and delivery of both isoforms. This precision is pivotal for secure gene therapy involving structural proteins like FAM161A.
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Affiliation(s)
- Yvan Arsenijevic
- Unit of Retinal Degeneration and Regeneration, Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland.
| | - Ning Chang
- Unit of Retinal Degeneration and Regeneration, Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
- Group for Retinal Disorder Research, Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - Olivier Mercey
- University of Geneva, Department of Molecular and Cellular Biology, Sciences III, Geneva, Switzerland
| | - Younes El Fersioui
- Unit of Retinal Degeneration and Regeneration, Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
- Group for Retinal Disorder Research, Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - Hanna Koskiniemi-Kuendig
- Unit of Retinal Degeneration and Regeneration, Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - Caroline Joubert
- Unit of Retinal Degeneration and Regeneration, Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - Alexis-Pierre Bemelmans
- Université Paris-Saclay, CEA, CNRS, Laboratoire des Maladies Neurodégénératives: mécanismes, thérapies, imagerie, Fontenay-aux-Roses, France
| | - Carlo Rivolta
- Institute of Molecular and Clinical Ophthalmology Basel (IOB), Basel, Switzerland
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Eyal Banin
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Faculty of Medicine, The Hebrew of Jerusalem, Jerusalem, Israel
| | - Dror Sharon
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Faculty of Medicine, The Hebrew of Jerusalem, Jerusalem, Israel
| | - Paul Guichard
- University of Geneva, Department of Molecular and Cellular Biology, Sciences III, Geneva, Switzerland
| | - Virginie Hamel
- University of Geneva, Department of Molecular and Cellular Biology, Sciences III, Geneva, Switzerland
| | - Corinne Kostic
- Group for Retinal Disorder Research, Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland.
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3
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Truong HM, Cruz-Colón KO, Martínez-Márquez JY, Willer JR, Travis AM, Biswas SK, Lo WK, Bolz HJ, Pearring JN. The tectonic complex regulates membrane protein composition in the photoreceptor cilium. Nat Commun 2023; 14:5671. [PMID: 37704658 PMCID: PMC10500017 DOI: 10.1038/s41467-023-41450-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 08/30/2023] [Indexed: 09/15/2023] Open
Abstract
The primary cilium is a signaling organelle with a unique membrane composition maintained by a diffusional barrier residing at the transition zone. Many transition zone proteins, such as the tectonic complex, are linked to preserving ciliary composition but the mechanism remains unknown. To understand tectonic's role, we generate a photoreceptor-specific Tctn1 knockout mouse. Loss of Tctn1 results in the absence of the entire tectonic complex and associated MKS proteins yet has minimal effects on the transition zone structure of rod photoreceptors. We find that the protein composition of the photoreceptor cilium is disrupted as non-resident membrane proteins accumulate in the cilium over time, ultimately resulting in photoreceptor degeneration. We further show that fluorescent rhodopsin moves faster through the transition zone in photoreceptors lacking tectonic, which suggests that the tectonic complex acts as a physical barrier to slow down membrane protein diffusion in the photoreceptor transition zone to ensure proper removal of non-resident membrane proteins.
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Affiliation(s)
- Hanh M Truong
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI, USA
| | - Kevin O Cruz-Colón
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, USA
| | | | - Jason R Willer
- Department of Ophthalmology and Visual Science, University of Michigan, Ann Arbor, MI, USA
| | - Amanda M Travis
- Department of Ophthalmology and Visual Science, University of Michigan, Ann Arbor, MI, USA
| | - Sondip K Biswas
- Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA, USA
| | - Woo-Kuen Lo
- Department of Neurobiology, Morehouse School of Medicine, Atlanta, GA, USA
| | - Hanno J Bolz
- Senckenberg Centre for Human Genetics, Frankfurt am Main, Germany
- Institute of Human Genetics, University Hospital of Cologne, Cologne, Germany
| | - Jillian N Pearring
- Department of Ophthalmology and Visual Science, University of Michigan, Ann Arbor, MI, USA.
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI, USA.
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4
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Zhu T, Zhang Y, Sheng X, Zhang X, Chen Y, Zhu H, Guo Y, Qi Y, Zhao Y, Zhou Q, Chen X, Guo X, Zhao C. Absence of CEP78 causes photoreceptor and sperm flagella impairments in mice and a human individual. eLife 2023; 12:76157. [PMID: 36756949 PMCID: PMC9984195 DOI: 10.7554/elife.76157] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 02/07/2023] [Indexed: 02/10/2023] Open
Abstract
Cone-rod dystrophy (CRD) is a genetically inherited retinal disease that can be associated with male infertility, while the specific genetic mechanisms are not well known. Here, we report CEP78 as a causative gene of a particular syndrome including CRD and male infertility with multiple morphological abnormalities of sperm flagella (MMAF) both in human and mouse. Cep78 knockout mice exhibited impaired function and morphology of photoreceptors, typified by reduced ERG amplitudes, disrupted translocation of cone arrestin, attenuated and disorganized photoreceptor outer segments (OS) disks and widen OS bases, as well as interrupted connecting cilia elongation and abnormal structures. Cep78 deletion also caused male infertility and MMAF, with disordered '9+2' structure and triplet microtubules in sperm flagella. Intraflagellar transport (IFT) proteins IFT20 and TTC21A are identified as interacting proteins of CEP78. Furthermore, CEP78 regulated the interaction, stability, and centriolar localization of its interacting protein. Insufficiency of CEP78 or its interacting protein causes abnormal centriole elongation and cilia shortening. Absence of CEP78 protein in human caused similar phenotypes in vision and MMAF as Cep78-/- mice. Collectively, our study supports the important roles of CEP78 defects in centriole and ciliary dysfunctions and molecular pathogenesis of such multi-system syndrome.
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Affiliation(s)
- Tianyu Zhu
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Gusu School, Nanjing Medical UniversityNanjingChina
| | - Yuxin Zhang
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Shanghai Medical College, Fudan UniversityShanghaiChina
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical UniversityNanjingChina
| | - Xunlun Sheng
- Gansu Aier Ophthalmiology and Optometry HospitalLanzhouChina
- Ningxia Eye Hospital, People’s Hospital of Ningxia Hui Autonomous Region, Third Clinical Medical College of Ningxia Medical UniversityYinchuanChina
| | - Xiangzheng Zhang
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Gusu School, Nanjing Medical UniversityNanjingChina
| | - Yu Chen
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Gusu School, Nanjing Medical UniversityNanjingChina
| | - Hongjing Zhu
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical UniversityNanjingChina
| | - Yueshuai Guo
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Gusu School, Nanjing Medical UniversityNanjingChina
| | - Yaling Qi
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Gusu School, Nanjing Medical UniversityNanjingChina
| | - Yichen Zhao
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Gusu School, Nanjing Medical UniversityNanjingChina
| | - Qi Zhou
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Gusu School, Nanjing Medical UniversityNanjingChina
| | - Xue Chen
- Department of Ophthalmology, The First Affiliated Hospital of Nanjing Medical University, Nanjing Medical UniversityNanjingChina
| | - Xuejiang Guo
- State Key Laboratory of Reproductive Medicine, Department of Histology and Embryology, Gusu School, Nanjing Medical UniversityNanjingChina
| | - Chen Zhao
- Department of Ophthalmology and Vision Science, Eye & ENT Hospital, Shanghai Medical College, Fudan UniversityShanghaiChina
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5
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Gopalakrishnan P, Beryozkin A, Banin E, Sharon D. Morphological and Functional Comparison of Mice Models for Retinitis Pigmentosa. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1415:365-370. [PMID: 37440058 DOI: 10.1007/978-3-031-27681-1_53] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Retinitis pigmentosa (RP) is the predominant form of inherited retinal degenerations (IRDs) caused by abnormalities and loss of photoreceptor cells ensuing diminishment of vision. RP is a heterogenous genetic disorder associated with mutations in over 80 genes, showing various inheritance patterns. Laboratory mouse models are important for our understanding of disease mechanisms, modifier effects, and development of therapeutic modalities. In this review, we have summarized a comprehensive comparison of our previously reported Fam161a knockout (KO) mouse model with other well-studied RP mouse models, Fam161aGT/GT, Pde6brd1, Nr2e3rd7, Rpgrrd9, and Pde6brd10 using structural and functional analysis of the retina. Fam161atm1b/tm1b mouse models are important for developing novel therapies and mainly AAV-based gene therapy and translational read-through-inducing drugs.
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Affiliation(s)
- Prakadeeswari Gopalakrishnan
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Avigail Beryozkin
- 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.
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6
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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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7
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Retinal Structure and Function in a Knock-In Mouse Model for the FAM161A-p.Arg523* Human Nonsense Pathogenic Variant. OPHTHALMOLOGY SCIENCE 2022; 3:100229. [DOI: 10.1016/j.xops.2022.100229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Revised: 08/28/2022] [Accepted: 09/26/2022] [Indexed: 11/05/2022]
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8
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The Adhesion GPCR VLGR1/ADGRV1 Regulates the Ca2+ Homeostasis at Mitochondria-Associated ER Membranes. Cells 2022; 11:cells11182790. [PMID: 36139365 PMCID: PMC9496679 DOI: 10.3390/cells11182790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 08/25/2022] [Accepted: 09/01/2022] [Indexed: 11/17/2022] Open
Abstract
The very large G protein-coupled receptor (VLGR1, ADGRV1) is the largest member of the adhesion GPCR family. Mutations in VLGR1 have been associated with the human Usher syndrome (USH), the most common form of inherited deaf-blindness as well as childhood absence epilepsy. VLGR1 was previously found as membrane–membrane adhesion complexes and focal adhesions. Affinity proteomics revealed that in the interactome of VLGR1, molecules are enriched that are associated with both the ER and mitochondria, as well as mitochondria-associated ER membranes (MAMs), a compartment at the contact sites of both organelles. We confirmed the interaction of VLGR1 with key proteins of MAMs by pull-down assays in vitro complemented by in situ proximity ligation assays in cells. Immunocytochemistry by light and electron microscopy demonstrated the localization of VLGR1 in MAMs. The absence of VLGR1 in tissues and cells derived from VLGR1-deficient mouse models resulted in alterations in the MAM architecture and in the dysregulation of the Ca2+ transient from ER to mitochondria. Our data demonstrate the molecular and functional interaction of VLGR1 with components in MAMs and point to an essential role of VLGR1 in the regulation of Ca2+ homeostasis, one of the key functions of MAMs.
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9
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Faber S, Roepman R. A defective structural zipper in photoreceptors causes inherited blindness. PLoS Biol 2022; 20:e3001672. [PMID: 35714125 PMCID: PMC9205488 DOI: 10.1371/journal.pbio.3001672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
This Primer explores a PLOS Biology study which uses ultrastructure expansion microscopy to study the inner scaffold of the photoreceptor connecting cilium, the location of multiple proteins implicated in inherited forms of progressive sight loss such as retinitis pigmentosa and Leber congenital amaurosis.
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Affiliation(s)
- Siebren Faber
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Ronald Roepman
- Department of Human Genetics and Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, the Netherlands
- * E-mail:
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10
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Mercey O, Kostic C, Bertiaux E, Giroud A, Sadian Y, Gaboriau DCA, Morrison CG, Chang N, Arsenijevic Y, Guichard P, Hamel V. The connecting cilium inner scaffold provides a structural foundation that protects against retinal degeneration. PLoS Biol 2022; 20:e3001649. [PMID: 35709082 PMCID: PMC9202906 DOI: 10.1371/journal.pbio.3001649] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 04/27/2022] [Indexed: 12/17/2022] Open
Abstract
Inherited retinal degeneration due to loss of photoreceptor cells is a leading cause of human blindness. These cells possess a photosensitive outer segment linked to the cell body through the connecting cilium (CC). While structural defects of the CC have been associated with retinal degeneration, its nanoscale molecular composition, assembly, and function are barely known. Here, using expansion microscopy and electron microscopy, we reveal the molecular architecture of the CC and demonstrate that microtubules are linked together by a CC inner scaffold containing POC5, CENTRIN, and FAM161A. Dissecting CC inner scaffold assembly during photoreceptor development in mouse revealed that it acts as a structural zipper, progressively bridging microtubule doublets and straightening the CC. Furthermore, we show that Fam161a disruption in mouse leads to specific CC inner scaffold loss and triggers microtubule doublet spreading, prior to outer segment collapse and photoreceptor degeneration, suggesting a molecular mechanism for a subtype of retinitis pigmentosa. Inherited retinal degeneration due to loss of photoreceptor cells is a leading cause of human blindness. Ultrastructure expansion microscopy on mouse retina reveals the presence of a novel structure inside the photoreceptor connecting cilium, the inner scaffold, that protects the outer segment against degeneration.
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Affiliation(s)
- Olivier Mercey
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Corinne Kostic
- Group for Retinal Disorder Research, Department of Ophthalmology, University Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - Eloïse Bertiaux
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Alexia Giroud
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Yashar Sadian
- CryoGenic Facility, University of Geneva, Geneva, Switzerland
| | - David C. A. Gaboriau
- Centre for Chromosome Biology, National University of Ireland Galway, Galway, Ireland
| | - Ciaran G. Morrison
- Centre for Chromosome Biology, National University of Ireland Galway, Galway, Ireland
| | - Ning Chang
- Unit of Retinal Degeneration and Regeneration, Department of Ophthalmology, University Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - Yvan Arsenijevic
- Unit of Retinal Degeneration and Regeneration, Department of Ophthalmology, University Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, Lausanne, Switzerland
| | - Paul Guichard
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
- * E-mail: (PG); (VH)
| | - Virginie Hamel
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
- * E-mail: (PG); (VH)
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11
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Dewees SI, Vargová R, Hardin KR, Turn RE, Devi S, Linnert J, Wolfrum U, Caspary T, Eliáš M, Kahn RA. Phylogenetic profiling and cellular analyses of ARL16 reveal roles in traffic of IFT140 and INPP5E. Mol Biol Cell 2022; 33:ar33. [PMID: 35196065 PMCID: PMC9250359 DOI: 10.1091/mbc.e21-10-0509-t] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 01/11/2022] [Accepted: 02/18/2022] [Indexed: 12/14/2022] Open
Abstract
The ARF family of regulatory GTPases is ancient, with 16 members predicted to have been present in the last eukaryotic common ancestor. Our phylogenetic profiling of paralogues in diverse species identified four family members whose presence correlates with that of a cilium/flagellum: ARL3, ARL6, ARL13, and ARL16. No prior evidence links ARL16 to cilia or other cell functions, despite its presence throughout eukaryotes. Deletion of ARL16 in mouse embryonic fibroblasts (MEFs) results in decreased ciliogenesis yet increased ciliary length. We also found Arl16 knockout (KO) in MEFs to alter ciliary protein content, including loss of ARL13B, ARL3, INPP5E, and the IFT-A core component IFT140. Instead, both INPP5E and IFT140 accumulate at the Golgi in Arl16 KO lines, while other intraflagellar transport (IFT) proteins do not, suggesting a specific defect in traffic from Golgi to cilia. We propose that ARL16 regulates a Golgi-cilia traffic pathway and is required specifically in the export of IFT140 and INPP5E from the Golgi.
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Affiliation(s)
- Skylar I. Dewees
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Laney Graduate School, Emory University, Atlanta, GA 30307
| | - Romana Vargová
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, CZ-710 00, Ostrava, Czech Republic
| | - Katherine R. Hardin
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Laney Graduate School, Emory University, Atlanta, GA 30307
| | - Rachel E. Turn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Laney Graduate School, Emory University, Atlanta, GA 30307
- Department of Microbiology and Immunology, Stanford University, Palo Alto, CA 94305-5124
| | - Saroja Devi
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Joshua Linnert
- Institute of Molecular Physiology, Johannes Gutenberg University, Mainz 55128, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Johannes Gutenberg University, Mainz 55128, Germany
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322
| | - Marek Eliáš
- Department of Biology and Ecology, Faculty of Science, University of Ostrava, CZ-710 00, Ostrava, Czech Republic
| | - Richard A. Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
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12
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Beryozkin A, Samanta A, Gopalakrishnan P, Khateb S, Banin E, Sharon D, Nagel-Wolfrum K. Translational Read-Through Drugs (TRIDs) Are Able to Restore Protein Expression and Ciliogenesis in Fibroblasts of Patients with Retinitis Pigmentosa Caused by a Premature Termination Codon in FAM161A. Int J Mol Sci 2022; 23:ijms23073541. [PMID: 35408898 PMCID: PMC8998412 DOI: 10.3390/ijms23073541] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 03/17/2022] [Accepted: 03/21/2022] [Indexed: 02/04/2023] Open
Abstract
Ataluren and Gentamicin are translational readthrough drugs (TRIDs) that induce premature termination codon (PTC) readthrough, resulting in the production of full-length proteins that usually harbor a single missense substitution. FAM161A is a ciliary protein which is expressed in photoreceptors, and pathogenic variants in this gene cause retinitis pigmentosa (RP). Applying TRIDs on fibroblasts from RP patients due to PTC in the FAM161A (p.Arg523*) gene may uncover whether TRIDs can restore expression, localization and function of this protein. Fibroblasts from six patients and five age-matched controls were starved prior to treatment with ataluren or gentamicin, and later FAM161A expression, ciliogenesis and cilia length were analyzed. In contrast to control cells, fibroblasts of patients did not express the FAM161A protein, showed a lower percentage of ciliated cells and grew shorter cilia after starvation. Ataluren and Gentamicin treatment were able to restore FAM161A expression, localization and co-localization with α-tubulin. Ciliogenesis and cilia length were restored following Ataluren treatment almost up to a level which was observed in control cells. Gentamicin was less efficient in ciliogenesis compared to Ataluren. Our results provide a proof-of-concept that PTCs in FAM161A can be effectively suppressed by Ataluren or Gentamicin, resulting in a full-length functional protein.
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Affiliation(s)
- Avigail Beryozkin
- Hadassah Medical Center, Department of Ophthalmology, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel; (A.B.); (P.G.); (S.K.); (E.B.); (D.S.)
| | - Ananya Samanta
- Institute of Molecular Physiology, Johannes Gutenberg University of Mainz, 55122 Mainz, Germany;
- Institute of Development Biology and Neurobiology, Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
| | - Prakadeeswari Gopalakrishnan
- Hadassah Medical Center, Department of Ophthalmology, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel; (A.B.); (P.G.); (S.K.); (E.B.); (D.S.)
| | - Samer Khateb
- Hadassah Medical Center, Department of Ophthalmology, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel; (A.B.); (P.G.); (S.K.); (E.B.); (D.S.)
| | - Eyal Banin
- Hadassah Medical Center, Department of Ophthalmology, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel; (A.B.); (P.G.); (S.K.); (E.B.); (D.S.)
| | - Dror Sharon
- Hadassah Medical Center, Department of Ophthalmology, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 91120, Israel; (A.B.); (P.G.); (S.K.); (E.B.); (D.S.)
| | - Kerstin Nagel-Wolfrum
- Institute of Molecular Physiology, Johannes Gutenberg University of Mainz, 55122 Mainz, Germany;
- Institute of Development Biology and Neurobiology, Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
- Correspondence:
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13
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Grotz S, Schäfer J, Wunderlich KA, Ellederova Z, Auch H, Bähr A, Runa-Vochozkova P, Fadl J, Arnold V, Ardan T, Veith M, Santamaria G, Dhom G, Hitzl W, Kessler B, Eckardt C, Klein J, Brymova A, Linnert J, Kurome M, Zakharchenko V, Fischer A, Blutke A, Döring A, Suchankova S, Popelar J, Rodríguez-Bocanegra E, Dlugaiczyk J, Straka H, May-Simera H, Wang W, Laugwitz KL, Vandenberghe LH, Wolf E, Nagel-Wolfrum K, Peters T, Motlik J, Fischer MD, Wolfrum U, Klymiuk N. Early disruption of photoreceptor cell architecture and loss of vision in a humanized pig model of usher syndromes. EMBO Mol Med 2022; 14:e14817. [PMID: 35254721 PMCID: PMC8988205 DOI: 10.15252/emmm.202114817] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 02/04/2022] [Accepted: 02/09/2022] [Indexed: 01/17/2023] Open
Abstract
Usher syndrome (USH) is the most common form of monogenic deaf-blindness. Loss of vision is untreatable and there are no suitable animal models for testing therapeutic strategies of the ocular constituent of USH, so far. By introducing a human mutation into the harmonin-encoding USH1C gene in pigs, we generated the first translational animal model for USH type 1 with characteristic hearing defect, vestibular dysfunction, and visual impairment. Changes in photoreceptor architecture, quantitative motion analysis, and electroretinography were characteristics of the reduced retinal virtue in USH1C pigs. Fibroblasts from USH1C pigs or USH1C patients showed significantly elongated primary cilia, confirming USH as a true and general ciliopathy. Primary cells also proved their capacity for assessing the therapeutic potential of CRISPR/Cas-mediated gene repair or gene therapy in vitro. AAV-based delivery of harmonin into the eye of USH1C pigs indicated therapeutic efficacy in vivo.
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Affiliation(s)
- Sophia Grotz
- Chair of Molecular Animal Breeding and Biotechnology, LMU Munich, Munich, Germany.,Center for Innovative Medical Models, LMU Munich, Munich, Germany
| | - Jessica Schäfer
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg University (JGU), Mainz, Germany
| | - Kirsten A Wunderlich
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg University (JGU), Mainz, Germany
| | - Zdenka Ellederova
- Institute of Animal Physiology and Genetics, Czech Academy of Science, Libechov, Czech Republic
| | - Hannah Auch
- Chair of Molecular Animal Breeding and Biotechnology, LMU Munich, Munich, Germany.,Center for Innovative Medical Models, LMU Munich, Munich, Germany
| | - Andrea Bähr
- Center for Innovative Medical Models, LMU Munich, Munich, Germany.,Large Animal Models in Cardiovascular Research, Internal Medical Department I, TU Munich, Munich, Germany
| | - Petra Runa-Vochozkova
- Large Animal Models in Cardiovascular Research, Internal Medical Department I, TU Munich, Munich, Germany
| | - Janet Fadl
- Chair of Molecular Animal Breeding and Biotechnology, LMU Munich, Munich, Germany.,Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg University (JGU), Mainz, Germany
| | - Vanessa Arnold
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg University (JGU), Mainz, Germany
| | - Taras Ardan
- Institute of Animal Physiology and Genetics, Czech Academy of Science, Libechov, Czech Republic
| | - Miroslav Veith
- Ophthalmology Clinic, University Hospital Kralovske Vinohrady, Praha, Czech Republic
| | - Gianluca Santamaria
- Large Animal Models in Cardiovascular Research, Internal Medical Department I, TU Munich, Munich, Germany
| | - Georg Dhom
- Chair of Molecular Animal Breeding and Biotechnology, LMU Munich, Munich, Germany.,Center for Innovative Medical Models, LMU Munich, Munich, Germany
| | - Wolfgang Hitzl
- Biostatistics and Data Science, Paracelsus Medical University, Salzburg, Austria
| | - Barbara Kessler
- Chair of Molecular Animal Breeding and Biotechnology, LMU Munich, Munich, Germany.,Center for Innovative Medical Models, LMU Munich, Munich, Germany
| | - Christian Eckardt
- Center for Innovative Medical Models, LMU Munich, Munich, Germany.,Large Animal Models in Cardiovascular Research, Internal Medical Department I, TU Munich, Munich, Germany
| | - Joshua Klein
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg University (JGU), Mainz, Germany
| | - Anna Brymova
- Institute of Animal Physiology and Genetics, Czech Academy of Science, Libechov, Czech Republic
| | - Joshua Linnert
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg University (JGU), Mainz, Germany
| | - Mayuko Kurome
- Chair of Molecular Animal Breeding and Biotechnology, LMU Munich, Munich, Germany.,Center for Innovative Medical Models, LMU Munich, Munich, Germany
| | - Valeri Zakharchenko
- Chair of Molecular Animal Breeding and Biotechnology, LMU Munich, Munich, Germany.,Center for Innovative Medical Models, LMU Munich, Munich, Germany
| | - Andrea Fischer
- Veterinary Faculty, Small Animal Clinics, LMU Munich, Munich, Germany
| | - Andreas Blutke
- Institute of Experimental Genetics, Helmholtz Center Munich, Neuherberg, Germany
| | - Anna Döring
- Veterinary Faculty, Small Animal Clinics, LMU Munich, Munich, Germany
| | - Stepanka Suchankova
- Institute of Experimental Medicine, Czech Academy of Science, Prague, Czech Republic
| | - Jiri Popelar
- Institute of Experimental Medicine, Czech Academy of Science, Prague, Czech Republic
| | - Eduardo Rodríguez-Bocanegra
- Centre for Ophthalmology, University Eye Hospital, University Hospital Tübingen, Tübingen, Germany.,Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Julia Dlugaiczyk
- Department of Otorhinolaryngology, Head and Neck Surgery, University Hospital Zurich (USZ), University of Zurich, Zurich, Switzerland
| | - Hans Straka
- Faculty of Biology, LMU Munich, Planegg, Germany
| | - Helen May-Simera
- Institute of Molecular Physiology, Cilia Biology, JGU Mainz, Mainz, Germany
| | - Weiwei Wang
- Grousbeck Gene Therapy Center, Mass Eye and Ear and Harvard Medical School, Boston, MA, USA
| | - Karl-Ludwig Laugwitz
- Large Animal Models in Cardiovascular Research, Internal Medical Department I, TU Munich, Munich, Germany
| | - Luk H Vandenberghe
- Grousbeck Gene Therapy Center, Mass Eye and Ear and Harvard Medical School, Boston, MA, USA
| | - Eckhard Wolf
- Chair of Molecular Animal Breeding and Biotechnology, LMU Munich, Munich, Germany.,Center for Innovative Medical Models, LMU Munich, Munich, Germany
| | - Kerstin Nagel-Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg University (JGU), Mainz, Germany.,Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University (JGU), Mainz, Germany
| | - Tobias Peters
- Centre for Ophthalmology, University Eye Hospital, University Hospital Tübingen, Tübingen, Germany.,Institute for Ophthalmic Research, Centre for Ophthalmology, University Hospital Tübingen, Tübingen, Germany
| | - Jan Motlik
- Institute of Animal Physiology and Genetics, Czech Academy of Science, Libechov, Czech Republic
| | - M Dominik Fischer
- Oxford Eye Hospital, Oxford University NHS Foundation Trust, Oxford, UK.,Nuffield Laboratory of Ophthalmology, NDCN, University of Oxford, Oxford, UK
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg University (JGU), Mainz, Germany
| | - Nikolai Klymiuk
- Center for Innovative Medical Models, LMU Munich, Munich, Germany.,Large Animal Models in Cardiovascular Research, Internal Medical Department I, TU Munich, Munich, Germany
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14
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Turn RE, Hu Y, Dewees SI, Devi N, East MP, Hardin KR, Khatib T, Linnert J, Wolfrum U, Lim MJ, Casanova JE, Caspary T, Kahn RA. The ARF GAPs ELMOD1 and ELMOD3 act at the Golgi and cilia to regulate ciliogenesis and ciliary protein traffic. Mol Biol Cell 2022; 33:ar13. [PMID: 34818063 PMCID: PMC9236152 DOI: 10.1091/mbc.e21-09-0443] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/16/2021] [Accepted: 11/19/2021] [Indexed: 11/11/2022] Open
Abstract
ELMODs are a family of three mammalian paralogues that display GTPase-activating protein (GAP) activity toward a uniquely broad array of ADP-ribosylation factor (ARF) family GTPases that includes ARF-like (ARL) proteins. ELMODs are ubiquitously expressed in mammalian tissues, highly conserved across eukaryotes, and ancient in origin, being present in the last eukaryotic common ancestor. We described functions of ELMOD2 in immortalized mouse embryonic fibroblasts (MEFs) in the regulation of cell division, microtubules, ciliogenesis, and mitochondrial fusion. Here, using similar strategies with the paralogues ELMOD1 and ELMOD3, we identify novel functions and locations of these cell regulators and compare them to those of ELMOD2, allowing the determination of functional redundancy among the family members. We found strong similarities in phenotypes resulting from deletion of either Elmod1 or Elmod3 and marked differences from those arising in Elmod2 deletion lines. Deletion of either Elmod1 or Elmod3 results in the decreased ability of cells to form primary cilia, loss of a subset of proteins from cilia, and accumulation of some ciliary proteins at the Golgi, predicted to result from compromised traffic from the Golgi to cilia. These phenotypes are reversed upon activating mutant expression of either ARL3 or ARL16, linking their roles to ELMOD1/3 actions.
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Affiliation(s)
- Rachel E. Turn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Emory University, Atlanta, GA 30322
- Department of Microbiology and Immunology, Stanford University, Palo Alto, CA 94305
| | - Yihan Hu
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Department of Otolaryngology, Xiangya Hospital, Central South University, Changsha, 410008 Hunan, China
| | - Skylar I. Dewees
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Emory University, Atlanta, GA 30322
| | - Narra Devi
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
| | - Michael P. East
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599
| | - Katherine R. Hardin
- Department of Cell Biology, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Emory University, Atlanta, GA 30322
| | - Tala Khatib
- Department of Hematology and Medical Oncology, Emory University School of Medicine, Atlanta, GA 30322
- Biochemistry, Cell & Developmental Biology Graduate Program, Emory University, Atlanta, GA 30322
| | - Joshua Linnert
- Institute of Molecular Physiology, Johannes Gutenberg University, Mainz 55128, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Johannes Gutenberg University, Mainz 55128, Germany
| | - Michael J. Lim
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908
| | - James E. Casanova
- Department of Cell Biology, University of Virginia, Charlottesville, VA 22908
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322
| | - Richard A. Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
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15
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Turn RE, Linnert J, Gigante ED, Wolfrum U, Caspary T, Kahn RA. Roles for ELMOD2 and Rootletin in ciliogenesis. Mol Biol Cell 2021; 32:800-822. [PMID: 33596093 PMCID: PMC8108518 DOI: 10.1091/mbc.e20-10-0635] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
ELMOD2 is a GTPase-activating protein with uniquely broad specificity for ARF family GTPases. We previously showed that it acts with ARL2 in mitochondrial fusion and microtubule stability and with ARF6 during cytokinesis. Mouse embryonic fibroblasts deleted for ELMOD2 also displayed changes in cilia-related processes including increased ciliation, multiciliation, ciliary morphology, ciliary signaling, centrin accumulation inside cilia, and loss of rootlets at centrosomes with loss of centrosome cohesion. Increasing ARL2 activity or overexpressing Rootletin reversed these defects, revealing close functional links between the three proteins. This was further supported by the findings that deletion of Rootletin yielded similar phenotypes, which were rescued upon increasing ARL2 activity but not ELMOD2 overexpression. Thus, we propose that ARL2, ELMOD2, and Rootletin all act in a common pathway that suppresses spurious ciliation and maintains centrosome cohesion. Screening a number of markers of steps in the ciliation pathway supports a model in which ELMOD2, Rootletin, and ARL2 act downstream of TTBK2 and upstream of CP110 to prevent spurious release of CP110 and to regulate ciliary vesicle docking. These data thus provide evidence supporting roles for ELMOD2, Rootletin, and ARL2 in the regulation of ciliary licensing.
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Affiliation(s)
- Rachel E Turn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322.,Biochemistry, Cell & Developmental Biology Graduate Program, Emory University, Atlanta, GA 30322
| | - Joshua Linnert
- Institut für Molekulare Physiologie, Johannes Gutenberg-Universität, Mainz 655099, Germany
| | - Eduardo D Gigante
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322.,Neuroscience Graduate Program, Emory University, Atlanta, GA 30322
| | - Uwe Wolfrum
- Institut für Molekulare Physiologie, Johannes Gutenberg-Universität, Mainz 655099, Germany
| | - Tamara Caspary
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322
| | - Richard A Kahn
- Department of Biochemistry, Emory University School of Medicine, Atlanta, GA 30322
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16
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Beryozkin A, Matsevich C, Obolensky A, Kostic C, Arsenijevic Y, Wolfrum U, Banin E, Sharon D. A new mouse model for retinal degeneration due to Fam161a deficiency. Sci Rep 2021; 11:2030. [PMID: 33479377 PMCID: PMC7820261 DOI: 10.1038/s41598-021-81414-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 01/04/2021] [Indexed: 01/08/2023] Open
Abstract
FAM161A mutations are the most common cause of inherited retinal degenerations in Israel. We generated a knockout (KO) mouse model, Fam161atm1b/tm1b, lacking the major exon #3 which was replaced by a construct that include LacZ under the expression of the Fam161a promoter. LacZ staining was evident in ganglion cells, inner and outer nuclear layers and inner and outer-segments of photoreceptors in KO mice. No immunofluorescence staining of Fam161a was evident in the KO retina. Visual acuity and electroretinographic (ERG) responses showed a gradual decrease between the ages of 1 and 8 months. Optical coherence tomography (OCT) showed thinning of the whole retina. Hypoautofluorescence and hyperautofluorescence pigments was observed in retinas of older mice. Histological analysis revealed a progressive degeneration of photoreceptors along time and high-resolution transmission electron microscopy (TEM) analysis showed that photoreceptor outer segment disks were disorganized in a perpendicular orientation and outer segment base was wider and shorter than in WT mice. Molecular degenerative markers, such as microglia and CALPAIN-2, appear already in a 1-month old KO retina. These results indicate that a homozygous Fam161a frameshift mutation affects retinal function and causes retinal degeneration. This model will be used for gene therapy treatment in the future.
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Affiliation(s)
- Avigail Beryozkin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Jerusalem, Israel
| | - Chen Matsevich
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Jerusalem, Israel
| | - Alexey Obolensky
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Jerusalem, Israel
| | - Corinne Kostic
- Department of Ophthalmology, Jules-Gonin Eye Hospital, University of Lausanne, 1004, Lausanne, Switzerland
| | - Yvan Arsenijevic
- Department of Ophthalmology, Jules-Gonin Eye Hospital, University of Lausanne, 1004, Lausanne, Switzerland
| | - Uwe Wolfrum
- Institute for Molecular Physiology, Johannes Gutenberg University, 55128, Mainz, Germany
| | - Eyal Banin
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Jerusalem, Israel.
| | - Dror Sharon
- Department of Ophthalmology, Hadassah Medical Center, Faculty of Medicine, The Hebrew University of Jerusalem, 91120, Jerusalem, Israel.
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17
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Le Guennec M, Klena N, Gambarotto D, Laporte MH, Tassin AM, van den Hoek H, Erdmann PS, Schaffer M, Kovacik L, Borgers S, Goldie KN, Stahlberg H, Bornens M, Azimzadeh J, Engel BD, Hamel V, Guichard P. A helical inner scaffold provides a structural basis for centriole cohesion. SCIENCE ADVANCES 2020; 6:eaaz4137. [PMID: 32110738 PMCID: PMC7021493 DOI: 10.1126/sciadv.aaz4137] [Citation(s) in RCA: 86] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 12/03/2019] [Indexed: 05/10/2023]
Abstract
The ninefold radial arrangement of microtubule triplets (MTTs) is the hallmark of the centriole, a conserved organelle crucial for the formation of centrosomes and cilia. Although strong cohesion between MTTs is critical to resist forces applied by ciliary beating and the mitotic spindle, how the centriole maintains its structural integrity is not known. Using cryo-electron tomography and subtomogram averaging of centrioles from four evolutionarily distant species, we found that MTTs are bound together by a helical inner scaffold covering ~70% of the centriole length that maintains MTTs cohesion under compressive forces. Ultrastructure Expansion Microscopy (U-ExM) indicated that POC5, POC1B, FAM161A, and Centrin-2 localize to the scaffold structure along the inner wall of the centriole MTTs. Moreover, we established that these four proteins interact with each other to form a complex that binds microtubules. Together, our results provide a structural and molecular basis for centriole cohesion and geometry.
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Affiliation(s)
- Maeva Le Guennec
- University of Geneva, Department of Cell Biology, Sciences III, Geneva, Switzerland
| | - Nikolai Klena
- University of Geneva, Department of Cell Biology, Sciences III, Geneva, Switzerland
| | - Davide Gambarotto
- University of Geneva, Department of Cell Biology, Sciences III, Geneva, Switzerland
| | - Marine H. Laporte
- University of Geneva, Department of Cell Biology, Sciences III, Geneva, Switzerland
| | - Anne-Marie Tassin
- Institute for Integrative Biology of the Cell (I2BC), CEA, CNRS, Univ. Paris Sud, Université Paris-Saclay, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette, France
| | - Hugo van den Hoek
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Philipp S. Erdmann
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Miroslava Schaffer
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Lubomir Kovacik
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel CH-4058, Switzerland
| | - Susanne Borgers
- University of Geneva, Department of Cell Biology, Sciences III, Geneva, Switzerland
| | - Kenneth N. Goldie
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel CH-4058, Switzerland
| | - Henning Stahlberg
- Center for Cellular Imaging and NanoAnalytics (C-CINA), Biozentrum, University of Basel, Basel CH-4058, Switzerland
| | - Michel Bornens
- Institut Curie, PSL Research University, CNRS-UMR 144, 75005 Paris, France
| | - Juliette Azimzadeh
- Université de Paris, Institut Jacques Monod, CNRS UMR7592, 75013 Paris, France
| | - Benjamin D. Engel
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Ingolstädter Landstraße 1, 85764 Neuherberg, Germany
- Corresponding author. (B.D.E.); (V.H.); (P.G.)
| | - Virginie Hamel
- University of Geneva, Department of Cell Biology, Sciences III, Geneva, Switzerland
- Corresponding author. (B.D.E.); (V.H.); (P.G.)
| | - Paul Guichard
- University of Geneva, Department of Cell Biology, Sciences III, Geneva, Switzerland
- Corresponding author. (B.D.E.); (V.H.); (P.G.)
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18
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Litwińska Z, Sobuś A, Łuczkowska K, Grabowicz A, Mozolewska-Piotrowska K, Safranow K, Kawa MP, Machaliński B, Machalińska A. The Interplay Between Systemic Inflammatory Factors and MicroRNAs in Age-Related Macular Degeneration. Front Aging Neurosci 2019; 11:286. [PMID: 31695606 PMCID: PMC6817913 DOI: 10.3389/fnagi.2019.00286] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 10/04/2019] [Indexed: 12/20/2022] Open
Abstract
We aimed to explore the expression of systemic inflammatory factors and selected intracellular miRNAs that regulate inflammatory signaling pathways potentially involved in age-related macular degeneration (AMD) pathogenesis. A total of 179 patients with wet AMD, 175 with dry AMD and 121 controls were enrolled in the study. Soluble inflammatory factors were analyzed in plasma samples using Luminex technology. Expression of selected miRNAs was analyzed in isolated nucleated peripheral blood cells (PBNCs) using real-time qPCR. Wet AMD was an independent factor associated with higher concentrations of IL-6 (β = +0.24, p = 0.0004), GM-CSF (β = +0.31, p < 0.001), IFN-γ (β = +0.58, p < 0.001), higher expression of miRNA-23a-3p (β = +0.60, p < 0.0001), miRNA-30b (β = +0.32, p < 0.0001), miRNA-191-5p (β = +0.28, p < 0.0001) and lower concentration of IL-1β (β = −0.25, p = 0.0003), IL-5 (β = −0.45, p < 0.001), IL-10 (β = −0.45, p < 0.001), IL-12 (β = −0.35, p < 0.001), lower expression of miRNA-16-5p (β = −0.31, p < 0.0001), miRNA-17-3p (β = −0.18, p = 0.01), miRNA-150-5p (β = −0.18, p = 0.01) and miRNA-155-5p (β = −0.47, p < 0.0001). Multivariate analysis revealed that dry AMD was an independent factor associated with higher concentration of GM-CSF (β = +0.34, p < 0.001), IL-6 (β = +0.13, p = 0.05), higher expression of miRNA-23a-3p (β = +0.60, p < 0.0001), miRNA-126-3p (β = +0.23, p = 0.0005), miRNA-126-5p (β = +0.16, p = 0.01), miRNA 146a (β = +0.14, p = 0.03), and mRNA191-5p (β = +0.15, p = 0.03) and lower concentrations of TNF-α (β = +0.24, p = 0.0004), IL-1β (β = −0.39, p < 0.001), IL-2 (β = −0.20, p = 0.003), IL-5 (β = −0.54, p < 0.001), IL-10 (β = −0.56, p < 0.001), IL-12 (β = −0.51, p < 0.001), lower expression of miRNA-16-5p (β = −0.23, p = 0.0004), miRNA-17-3p (β = −0.20, p = 0.003) and miRNA-17-5p (β = −0.19, p = 0.004). Negative correlations between visual acuity and WBC, lymphocyte count, TNF-α, IL-1 β, IL-2, IL-4, IL-6, IL-10 concentrations and miRNA-191-5p, as well as positive correlations between visual acuity and miRNA-126-3p, -126-5p, and -155-5p PBNCs expression were found in AMD patients. No such correlations were found in the control group. Our results may suggest the role of both intra- and extracellular mechanisms implicated in inflammatory response regulation in multifactorial AMD pathogenesis.
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Affiliation(s)
- Zofia Litwińska
- Department of General Pathology, Pomeranian Medical University, Szczecin, Poland
| | - Anna Sobuś
- Department of General Pathology, Pomeranian Medical University, Szczecin, Poland
| | - Karolina Łuczkowska
- Department of General Pathology, Pomeranian Medical University, Szczecin, Poland
| | - Aleksandra Grabowicz
- First Department of Ophthalmology, Pomeranian Medical University, Szczecin, Poland
| | | | - Krzysztof Safranow
- Department of Biochemistry and Medical Chemistry, Pomeranian Medical University, Szczecin, Poland
| | - Miłosz Piotr Kawa
- Department of General Pathology, Pomeranian Medical University, Szczecin, Poland
| | - Bogusław Machaliński
- Department of General Pathology, Pomeranian Medical University, Szczecin, Poland
| | - Anna Machalińska
- First Department of Ophthalmology, Pomeranian Medical University, Szczecin, Poland
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19
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Blond F, Léveillard T. Functional Genomics of the Retina to Elucidate its Construction and Deconstruction. Int J Mol Sci 2019; 20:E4922. [PMID: 31590277 PMCID: PMC6801968 DOI: 10.3390/ijms20194922] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 10/01/2019] [Indexed: 12/20/2022] Open
Abstract
The retina is the light sensitive part of the eye and nervous tissue that have been used extensively to characterize the function of the central nervous system. The retina has a central position both in fundamental biology and in the physiopathology of neurodegenerative diseases. We address the contribution of functional genomics to the understanding of retinal biology by reviewing key events in their historical perspective as an introduction to major findings that were obtained through the study of the retina using genomics, transcriptomics and proteomics. We illustrate our purpose by showing that most of the genes of interest for retinal development and those involved in inherited retinal degenerations have a restricted expression to the retina and most particularly to photoreceptors cells. We show that the exponential growth of data generated by functional genomics is a future challenge not only in terms of storage but also in terms of accessibility to the scientific community of retinal biologists in the future. Finally, we emphasize on novel perspectives that emerge from the development of redox-proteomics, the new frontier in retinal biology.
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Affiliation(s)
- Frédéric Blond
- Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
| | - Thierry Léveillard
- Department of Genetics, Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012 Paris, France.
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20
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Hu YS, Song H, Li Y, Xiao ZY, Li T. Whole-exome sequencing identifies novel mutations in genes responsible for retinitis pigmentosa in 2 nonconsanguineous Chinese families. Int J Ophthalmol 2019; 12:915-923. [PMID: 31236346 DOI: 10.18240/ijo.2019.06.06] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2018] [Accepted: 09/25/2018] [Indexed: 12/26/2022] Open
Abstract
AIM To detect the pathogenetic mutations responsible for nonsyndromic autosomal recessive retinitis pigmentosa (RP) in 2 nonconsanguineous Chinese families. METHODS The clinical data, including detailed medical history, best corrected visual acuity (BCVA), slit-lamp biomicroscope examination, fundus photography, optical coherence tomography, static perimetry, and full field electroretinogram, were collected from the members of 2 nonconsanguineous Chinese families preliminarily diagnosed with RP. Genomic DNA was extracted from the probands and other available family members; whole-exome sequencing was conducted with the DNA samples provided by the probands, and all mutations detected by whole-exome sequencing were verified using Sanger sequencing in the probands and the other available family members. The verified novel mutations were further sequenced in 192 ethnicity matched healthy controls. RESULTS The patients from the 2 families exhibited the typical symptoms of RP, including night blindness and progressive constriction of the visual field, and the fundus examinations showed attenuated retinal arterioles, peripheral bone spicule pigment deposits, and waxy optic discs. Whole-exome sequencing revealed a novel nonsense mutation in FAM161A (c.943A>T, p.Lys315*) and compound heterozygous mutations in RP1L1 (c.56C>A, p.Pro19His; c.5470C>T, p.Gln1824*). The nonsense c.5470C>T, p.Gln1824* mutation was novel. All mutations were verified by Sanger sequencing. The mutation p.Lys315* in FAM161A co-segregated with the phenotype, and all the nonsense mutations were absent from the ethnicity matched healthy controls and all available databases. CONCLUSION We identify 2 novel mutations in genes responsible for autosomal recessive RP, and the mutation in FAM161A is reported for the first time in a Chinese population. Our result not only enriches the knowledge of the mutation frequency and spectrum in the genes responsible for nonsyndromic RP but also provides a new target for future gene therapy.
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Affiliation(s)
- Yan-Shan Hu
- Department of Ophthalmology, the Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi 445000, Hubei Province, China
| | - Hui Song
- Department of Ophthalmology, the Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi 445000, Hubei Province, China
| | - Yin Li
- Department of Ophthalmology, the Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi 445000, Hubei Province, China
| | - Zi-Yun Xiao
- Department of Ophthalmology, the Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi 445000, Hubei Province, China
| | - Tuo Li
- Department of Ophthalmology, the Central Hospital of Enshi Autonomous Prefecture, Enshi Clinical College of Wuhan University, Enshi 445000, Hubei Province, China
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21
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Ying G, Frederick JM, Baehr W. Deletion of both centrin 2 (CETN2) and CETN3 destabilizes the distal connecting cilium of mouse photoreceptors. J Biol Chem 2019; 294:3957-3973. [PMID: 30647131 DOI: 10.1074/jbc.ra118.006371] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 01/09/2019] [Indexed: 02/03/2023] Open
Abstract
Centrins (CETN1-4) are ubiquitous and conserved EF-hand-family Ca2+-binding proteins associated with the centrosome, basal body, and transition zone. Deletion of CETN1 or CETN2 in mice causes male infertility or dysosmia, respectively, without affecting photoreceptor function. However, it remains unclear to what extent centrins are redundant with each other in photoreceptors. Here, to explore centrin redundancy, we generated Cetn3 GT/GT single-knockout and Cetn2 -/-;Cetn3 GT/GT double-knockout mice. Whereas the Cetn3 deletion alone did not affect photoreceptor function, simultaneous ablation of Cetn2 and Cetn3 resulted in attenuated scotopic and photopic electroretinography (ERG) responses in mice at 3 months of age, with nearly complete retina degeneration at 1 year. Removal of CETN2 and CETN3 activity from the lumen of the connecting cilium (CC) destabilized the photoreceptor axoneme and reduced the CC length as early as postnatal day 22 (P22). In Cetn2 -/-;Cetn3 GT/GT double-knockout mice, spermatogenesis-associated 7 (SPATA7), a key organizer of the photoreceptor-specific distal CC, was depleted gradually, and CETN1 was condensed to the mid-segment of the CC. Ultrastructural analysis revealed that in this double knockout, the axoneme of the CC expanded radially at the distal end, with vertically misaligned outer segment discs and membrane whorls. These observations suggest that CETN2 and CETN3 cooperate in stabilizing the CC/axoneme structure.
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Affiliation(s)
- Guoxin Ying
- From the Department of Ophthalmology, University of Utah Health Science Center, Salt Lake City, Utah 84132,
| | - Jeanne M Frederick
- From the Department of Ophthalmology, University of Utah Health Science Center, Salt Lake City, Utah 84132
| | - Wolfgang Baehr
- From the Department of Ophthalmology, University of Utah Health Science Center, Salt Lake City, Utah 84132, .,the Department of Neurobiology and Anatomy, University of Utah, Salt Lake City, Utah 84112, and.,the Department of Biology, University of Utah, Salt Lake City, Utah 84132
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22
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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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23
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Abstract
Microglia, the primary resident immune cell type, constitute a key population of glia in the retina. Recent evidence indicates that microglia play significant functional roles in the retina at different life stages. During development, retinal microglia regulate neuronal survival by exerting trophic influences and influencing programmed cell death. During adulthood, ramified microglia in the plexiform layers interact closely with synapses to maintain synaptic structure and function that underlie the retina's electrophysiological response to light. Under pathological conditions, retinal microglia participate in potentiating neurodegeneration in diseases such as glaucoma, retinitis pigmentosa, and age-related neurodegeneration by producing proinflammatory neurotoxic cytokines and removing living neurons via phagocytosis. Modulation of pathogenic microglial activation states and effector mechanisms has been linked to neuroprotection in animal models of retinal diseases. These findings have led to the design of early proof-of-concept clinical trials with microglial modulation as a therapeutic strategy.
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Affiliation(s)
- Sean M. Silverman
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;,
| | - Wai T. Wong
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892, USA;,
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24
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Dharmat R, Eblimit A, Robichaux MA, Zhang Z, Nguyen TMT, Jung SY, He F, Jain A, Li Y, Qin J, Overbeek P, Roepman R, Mardon G, Wensel TG, Chen R. SPATA7 maintains a novel photoreceptor-specific zone in the distal connecting cilium. J Cell Biol 2018; 217:2851-2865. [PMID: 29899041 PMCID: PMC6080925 DOI: 10.1083/jcb.201712117] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Revised: 05/09/2018] [Accepted: 05/23/2018] [Indexed: 12/25/2022] Open
Abstract
Photoreceptor-specific ciliopathies often affect a structure that is considered functionally homologous to the ciliary transition zone (TZ) called the connecting cilium (CC). However, it is unclear how mutations in certain ciliary genes disrupt the photoreceptor CC without impacting the primary cilia systemically. By applying stochastic optical reconstruction microscopy technology in different genetic models, we show that the CC can be partitioned into two regions: the proximal CC (PCC), which is homologous to the TZ of primary cilia, and the distal CC (DCC), a photoreceptor-specific extension of the ciliary TZ. This specialized distal zone of the CC in photoreceptors is maintained by SPATA7, which interacts with other photoreceptor-specific ciliary proteins such as RPGR and RPGRIP1. The absence of Spata7 results in the mislocalization of DCC proteins without affecting the PCC protein complexes. This collapse results in destabilization of the axonemal microtubules, which consequently results in photoreceptor degeneration. These data provide a novel mechanism to explain how genetic disruption of ubiquitously present ciliary proteins exerts tissue-specific ciliopathy phenotypes.
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Affiliation(s)
- Rachayata Dharmat
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX
| | - Aiden Eblimit
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX
| | - Michael A Robichaux
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Zhixian Zhang
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Thanh-Minh T Nguyen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Sung Yun Jung
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Feng He
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Antrix Jain
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Yumei Li
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX
| | - Jun Qin
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Paul Overbeek
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
| | - Ronald Roepman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, Netherlands
- Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Graeme Mardon
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Pathology and Immunology, Baylor College of Medicine, Houston, TX
| | - Theodore G Wensel
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
| | - Rui Chen
- Molecular and Human Genetics, Baylor College of Medicine, Houston, TX
- Human Genome Sequencing Center, Baylor College of Medicine, Houston, TX
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX
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25
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Rashid K, Wolf A, Langmann T. Microglia Activation and Immunomodulatory Therapies for Retinal Degenerations. Front Cell Neurosci 2018; 12:176. [PMID: 29977192 PMCID: PMC6021747 DOI: 10.3389/fncel.2018.00176] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Accepted: 06/05/2018] [Indexed: 01/05/2023] Open
Abstract
A chronic pro-inflammatory environment is a hallmark of retinal degenerative diseases and neurological disorders that affect vision. Inflammatory responses during retinal pathophysiology are orchestrated by microglial cells which constitute the resident immune cell population. Following activation, microglia cells lose their ramified protrusions, proliferate and rapidly migrate to the damaged areas and resolve tissue damage. However, sustained presence of tissue stress primes microglia to become overreactive and results in the excessive production of pro-inflammatory mediators that favor retinal degenerative changes. Consequently, interventions aimed at overriding microglial pro-inflammatory and pro-oxidative properties may attenuate photoreceptor demise and preserve retinal integrity. We highlight the positive effects of ligands for the translocator protein 18 kDa (TSPO) and the cytokine interferon beta (IFN-β) in modulating microgliosis during retinal pathologies and discuss their plausible mechanisms of action.
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Affiliation(s)
- Khalid Rashid
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Anne Wolf
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Cologne, Germany
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26
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Wilmes AT, Reinehr S, Kühn S, Pedreiturria X, Petrikowski L, Faissner S, Ayzenberg I, Stute G, Gold R, Dick HB, Kleiter I, Joachim SC. Laquinimod protects the optic nerve and retina in an experimental autoimmune encephalomyelitis model. J Neuroinflammation 2018; 15:183. [PMID: 29903027 PMCID: PMC6002998 DOI: 10.1186/s12974-018-1208-3] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2017] [Accepted: 05/20/2018] [Indexed: 12/11/2022] Open
Abstract
BACKGROUND The oral immunomodulatory agent laquinimod is currently evaluated for multiple sclerosis (MS) treatment. Phase II and III studies demonstrated a reduction of degenerative processes. In addition to anti-inflammatory effects, laquinimod might have neuroprotective properties, but its impact on the visual system, which is often affected by MS, is unknown. The aim of our study was to investigate potential protective effects of laquinimod on the optic nerve and retina in an experimental autoimmune encephalomyelitis (EAE) model. METHODS We induced EAE in C57/BL6 mice via MOG35-55 immunization. Animals were divided into an untreated EAE group, three EAE groups receiving laquinimod (1, 5, or 25 mg/kg daily), starting the day post-immunization, and a non-immunized control group. Thirty days post-immunization, scotopic electroretinograms were carried out, and mice were sacrificed for histopathology (HE, LFB), immunohistochemistry (MBP, Iba1, Tmem119, F4/80, GFAP, vimentin, Brn-3a, cleaved caspase 3) of the optic nerve and retina, and retinal qRT-PCR analyses (Brn-3a, Iba1, Tmem119, AMWAP, CD68, GFAP). To evaluate the effect of a therapeutic approach, EAE animals were treated with 25 mg/kg laquinimod from day 16 when 60% of the animals had developed clinical signs of EAE. RESULTS Laquinimod reduced neurological EAE symptoms and improved the neuronal electrical output of the inner nuclear layer compared to untreated EAE mice. Furthermore, cellular infiltration, especially recruited phagocytes, and demyelination in the optic nerve were reduced. Microglia were diminished in optic nerve and retina. Retinal macroglial signal was reduced under treatment, whereas in the optic nerve macroglia were not affected. Additionally, laquinimod preserved retinal ganglion cells and reduced apoptosis. A later treatment with laquinimod in a therapeutic approach led to a reduction of clinical signs and to an improved b-wave amplitude. However, no changes in cellular infiltration and demyelination of the optic nerves were observed. Also, the number of retinal ganglion cells remained unaltered. CONCLUSION From our study, we deduce neuroprotective and anti-inflammatory effects of laquinimod on the optic nerve and retina in EAE mice, when animals were treated before any clinical signs were noted. Given the fact that the visual system is frequently affected by MS, the agent might be an interesting subject of further neuro-ophthalmic investigations.
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Affiliation(s)
- Anna T Wilmes
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Sabrina Reinehr
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Sandra Kühn
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Xiomara Pedreiturria
- Department of Neurology, St. Josef-Hospital, Ruhr-University Bochum, Gudrunstrasse 56, 44791, Bochum, Germany
| | - Laura Petrikowski
- Department of Neurology, St. Josef-Hospital, Ruhr-University Bochum, Gudrunstrasse 56, 44791, Bochum, Germany
| | - Simon Faissner
- Department of Neurology, St. Josef-Hospital, Ruhr-University Bochum, Gudrunstrasse 56, 44791, Bochum, Germany
| | - Ilya Ayzenberg
- Department of Neurology, St. Josef-Hospital, Ruhr-University Bochum, Gudrunstrasse 56, 44791, Bochum, Germany
| | - Gesa Stute
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Ralf Gold
- Department of Neurology, St. Josef-Hospital, Ruhr-University Bochum, Gudrunstrasse 56, 44791, Bochum, Germany
| | - H Burkhard Dick
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany
| | - Ingo Kleiter
- Department of Neurology, St. Josef-Hospital, Ruhr-University Bochum, Gudrunstrasse 56, 44791, Bochum, Germany.
| | - Stephanie C Joachim
- Experimental Eye Research Institute, University Eye Hospital, Ruhr-University Bochum, In der Schornau 23-25, 44892, Bochum, Germany.
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27
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Rathnasamy G, Foulds WS, Ling EA, Kaur C. Retinal microglia - A key player in healthy and diseased retina. Prog Neurobiol 2018; 173:18-40. [PMID: 29864456 DOI: 10.1016/j.pneurobio.2018.05.006] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 03/09/2018] [Accepted: 05/29/2018] [Indexed: 01/04/2023]
Abstract
Microglia, the resident immune cells of the brain and retina, are constantly engaged in the surveillance of their surrounding neural tissue. During embryonic development they infiltrate the retinal tissues and participate in the phagocytosis of redundant neurons. The contribution of microglia in maintaining the purposeful and functional histo-architecture of the adult retina is indispensable. Within the retinal microenvironment, robust microglial activation is elicited by subtle changes caused by extrinsic and intrinsic factors. When there is a disturbance in the cell-cell communication between microglia and other retinal cells, for example in retinal injury, the activated microglia can manifest actions that can be detrimental. This is evidenced by activated microglia secreting inflammatory mediators that can further aggravate the retinal injury. Microglial activation as a harbinger of a variety of retinal diseases is well documented by many studies. In addition, a change in the microglial phenotype which may be associated with aging, may predispose the retina to age-related diseases. In light of the above, the focus of this review is to highlight the role played by microglia in the healthy and diseased retina, based on findings of our own work and from that of others.
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Affiliation(s)
- Gurugirijha Rathnasamy
- Department of Anatomy, Yong Loo Lin School of Medicine, Blk MD10, 4 Medical Drive, National University of Singapore, 117594, Singapore; Department of Ophthalmology and Visual Sciences, School of Medicine and Public Health, University of Wisconsin, Madison, WI, 53706, United States
| | - Wallace S Foulds
- Singapore Eye Research Institute Level 6, The Academia, Discovery Tower, 20 College Road, 169856, Singapore; University of Glasgow, Glasgow, Scotland, G12 8QQ, United Kingdom
| | - Eng-Ang Ling
- Department of Anatomy, Yong Loo Lin School of Medicine, Blk MD10, 4 Medical Drive, National University of Singapore, 117594, Singapore
| | - Charanjit Kaur
- Department of Anatomy, Yong Loo Lin School of Medicine, Blk MD10, 4 Medical Drive, National University of Singapore, 117594, Singapore.
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28
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McMurtrey JJ, Tso MOM. A review of the immunologic findings observed in retinitis pigmentosa. Surv Ophthalmol 2018; 63:769-781. [PMID: 29551596 DOI: 10.1016/j.survophthal.2018.03.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2017] [Revised: 03/12/2018] [Accepted: 03/12/2018] [Indexed: 12/20/2022]
Abstract
Most patients suffering from retinitis pigmentosa (RP) inherit the disorder; however, the immune-pathologic features associated with this disease have yet to be extensively studied. Six reports correlate antiretinal immune activity with vision deterioration in RP patients. Some of these patients have sporadic RP that occurs in excess of expected gene segregation during inheritance. The hypothesis that a primary immune-mediated disease process occurs in this sporadic group is supported by significant associations of RP with autoimmune endocrinopathies and other immune-related conditions or factors; however, no immunologic difference regarding RP family history is reported in the peripheral blood studies of RP patients. Twenty-one percent to 51% of RP patients display antiretinal antibodies, whereas 19-58% have antiretinal lymphocyte reactivity to retinal extract, and 60-85% have activated T cells. Mutations in animal models of RP have been shown to cause endoplasmic reticulum stress that may initiate immunopathology for genetic RP, but oxidative stress also encourages immune cytotoxicity. In addition, necrotic cell death is evident, which promotes inflammatory conditions. We review mechanisms and evidence for an occult inflammation in genetic RP and examine reports of efficacy in retarding RP progression with anti-inflammatory agents in clinical trials.
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Affiliation(s)
- John J McMurtrey
- The Wilmer Ophthalmological Institute, The Johns Hopkins University and Hospital, Baltimore, Maryland, USA.
| | - Mark O M Tso
- The Wilmer Ophthalmological Institute, The Johns Hopkins University and Hospital, Baltimore, Maryland, USA
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29
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Blank T, Goldmann T, Koch M, Amann L, Schön C, Bonin M, Pang S, Prinz M, Burnet M, Wagner JE, Biel M, Michalakis S. Early Microglia Activation Precedes Photoreceptor Degeneration in a Mouse Model of CNGB1-Linked Retinitis Pigmentosa. Front Immunol 2018; 8:1930. [PMID: 29354133 PMCID: PMC5760536 DOI: 10.3389/fimmu.2017.01930] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 12/15/2017] [Indexed: 01/12/2023] Open
Abstract
Retinitis pigmentosa (RP) denotes a family of inherited blinding eye diseases characterized by progressive degeneration of rod and cone photoreceptors in the retina. In most cases, a rod-specific genetic defect results in early functional loss and degeneration of rods, which is followed by degeneration of cones and loss of daylight vision at later stages. Microglial cells, the immune cells of the central nervous system, are activated in retinas of RP patients and in several RP mouse models. However, it is still a matter of debate whether activated microglial cells may be responsible for the amplification of the typical degenerative processes. Here, we used Cngb1−/− mice, which represent a slow degenerative mouse model of RP, to investigate the extent of microglia activation in retinal degeneration. With a combination of FACS analysis, immunohistochemistry and gene expression analysis we established that microglia in the Cngb1−/− retina were already activated in an early, predegenerative stage of the disease. The evidence available so far suggests that early retinal microglia activation represents a first step in RP, which might initiate or accelerate photoreceptor degeneration.
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Affiliation(s)
- Thomas Blank
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Tobias Goldmann
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,In Vivo Pharmacology, Synovo GmbH, Tübingen, Germany
| | - Mirja Koch
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Lukas Amann
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Christian Schön
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Michael Bonin
- Institute for Medical Genetics and Applied Genomics Transcriptomics, University of Tübingen, Tübingen, Germany.,IMGM Laboratories GmbH, Planegg, Germany
| | - Shengru Pang
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Marco Prinz
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany.,BIOSS Centre for Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | | | - Johanna E Wagner
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Martin Biel
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich CiPSM and Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, Munich, Germany
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30
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Abstract
Microgliosis is a hallmark of degenerative processes in the retina. Reactive microglia migrate to the photoreceptor layer and the subretinal space during outer retinal degeneration. This process creates a toxic milieu where reactive microglia and dying photoreceptors recruit additional reactive phagocytes. This results in the release of a multitude of proinflammatory factors which accelerate photoreceptor demise. In this chapter, we outline in detail how to monitor microgliosis in the Fam161a-deficient mouse model of Retinitis Pigmentosa by performing immunohistochemical stainings of retinal cryosections and flat mounts using the marker Iba1. This protocol will serve as a guideline in evaluating microglia reactivity and localization in various mouse models of retinal degeneration.
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31
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Seo S, Datta P. Photoreceptor outer segment as a sink for membrane proteins: hypothesis and implications in retinal ciliopathies. Hum Mol Genet 2017; 26:R75-R82. [PMID: 28453661 DOI: 10.1093/hmg/ddx163] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2017] [Accepted: 04/24/2017] [Indexed: 12/28/2022] Open
Abstract
The photoreceptor outer segment (OS) is a unique modification of the primary cilium, specialized for light perception. Being homologous organelles, the primary cilium and the OS share common building blocks and molecular machinery to construct and maintain them. The OS, however, has several unique structural features that are not seen in primary cilia. Although these unique features of the OS have been well documented, their implications in protein localization have been under-appreciated. In this review, we compare the structural properties of the primary cilium and the OS, and propose a hypothesis that the OS can act as a sink for membrane proteins. We further discuss the implications of this hypothesis in polarized protein localization in photoreceptors and mechanisms of photoreceptor degeneration in retinal ciliopathies.
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Affiliation(s)
- Seongjin Seo
- Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Poppy Datta
- Department of Ophthalmology and Visual Sciences, Wynn Institute for Vision Research, Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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32
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Karlstetter M, Dannhausen K, Langmann T. Mikroglia und Immuntherapien bei degenerativen Netzhauterkrankungen. MED GENET-BERLIN 2017. [DOI: 10.1007/s11825-017-0132-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Zusammenfassung
Bei allen bisher im Detail untersuchten erblichen Netzhautdegenerationen liegt eine dem Erkrankungsverlauf abträgliche chronische Aktivierung des angeborenen Immunsystems zugrunde. Vor allem residente Mikrogliazellen der Netzhaut und verschiedene Proteine des löslichen Komplementsystems tragen zu einer Schädigung von Photorezeptoren und retinalem Pigmentepithel bei. Sowohl spezifische Zielstrukturen auf reaktiven Immunzellen als auch fehlregulierte lösliche Immunmodulatoren bieten neue Ansatzpunkte für Therapien, um das Überleben der Netzhaut trotz genetischer Prädisposition zur Degeneration zu fördern. Dieser Beitrag gibt Einblick in die wesentlichen Regulationsmechanismen der Netzhautimmunologie, diskutiert die mögliche Verwendung immunologischer Biomarker für die Netzhautdiagnostik und zeigt immunmodulierende Therapieansätze durch Biologika und endogene Botenstoffe auf.
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Affiliation(s)
- Marcus Karlstetter
- Aff1 0000 0000 8852 305X grid.411097.a Lehrstuhl für Experimentelle Immunologie des Auges, Zentrum für Augenheilkunde Uniklinik Köln Joseph-Stelzmann-Str. 9 50931 Köln Deutschland
| | - Katharina Dannhausen
- Aff1 0000 0000 8852 305X grid.411097.a Lehrstuhl für Experimentelle Immunologie des Auges, Zentrum für Augenheilkunde Uniklinik Köln Joseph-Stelzmann-Str. 9 50931 Köln Deutschland
| | - Thomas Langmann
- Aff1 0000 0000 8852 305X grid.411097.a Lehrstuhl für Experimentelle Immunologie des Auges, Zentrum für Augenheilkunde Uniklinik Köln Joseph-Stelzmann-Str. 9 50931 Köln Deutschland
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May-Simera H, Nagel-Wolfrum K, Wolfrum U. Cilia - The sensory antennae in the eye. Prog Retin Eye Res 2017; 60:144-180. [PMID: 28504201 DOI: 10.1016/j.preteyeres.2017.05.001] [Citation(s) in RCA: 96] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 05/04/2017] [Accepted: 05/08/2017] [Indexed: 12/21/2022]
Abstract
Cilia are hair-like projections found on almost all cells in the human body. Originally believed to function merely in motility, the function of solitary non-motile (primary) cilia was long overlooked. Recent research has demonstrated that primary cilia function as signalling hubs that sense environmental cues and are pivotal for organ development and function, tissue hoemoestasis, and maintenance of human health. Cilia share a common anatomy and their diverse functional features are achieved by evolutionarily conserved functional modules, organized into sub-compartments. Defects in these functional modules are responsible for a rapidly growing list of human diseases collectively termed ciliopathies. Ocular pathogenesis is common in virtually all classes of syndromic ciliopathies, and disruptions in cilia genes have been found to be causative in a growing number of non-syndromic retinal dystrophies. This review will address what is currently known about cilia contribution to visual function. We will focus on the molecular and cellular functions of ciliary proteins and their role in the photoreceptor sensory cilia and their visual phenotypes. We also highlight other ciliated cell types in tissues of the eye (e.g. lens, RPE and Müller glia cells) discussing their possible contribution to disease progression. Progress in basic research on the cilia function in the eye is paving the way for therapeutic options for retinal ciliopathies. In the final section we describe the latest advancements in gene therapy, read-through of non-sense mutations and stem cell therapy, all being adopted to treat cilia dysfunction in the retina.
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Affiliation(s)
- Helen May-Simera
- Institute of Molecular Physiology, Cilia Biology, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Kerstin Nagel-Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology, Johannes Gutenberg-Universität Mainz, 55099 Mainz, Germany.
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34
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Abstract
The innate immune system is activated in a number of degenerative and inflammatory retinal disorders such as age-related macular degeneration (AMD). Retinal microglia, choroidal macrophages, and recruited monocytes, collectively termed 'retinal mononuclear phagocytes', are critical determinants of ocular disease outcome. Many publications have described the presence of these cells in mouse models for retinal disease; however, only limited aspects of their behavior have been uncovered, and these have only been uncovered using a single detection method. The workflow presented here describes a comprehensive analysis strategy that allows characterization of retinal mononuclear phagocytes in vivo and in situ. We present standardized working steps for scanning laser ophthalmoscopy of microglia from MacGreen reporter mice (mice expressing the macrophage colony-stimulating factor receptor GFP transgene throughout the mononuclear phagocyte system), quantitative analysis of Iba1-stained retinal sections and flat mounts, CD11b-based retinal flow cytometry, and qRT-PCR analysis of key microglia markers. The protocol can be completed within 3 d, and we present data from retinas treated with laser-induced choroidal neovascularization (CNV), bright white-light exposure, and Fam161a-associated inherited retinal degeneration. The assays can be applied to any of the existing mouse models for retinal disorders and may be valuable for documenting immune responses in studies for immunomodulatory therapies.
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35
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Broadgate S, Yu J, Downes SM, Halford S. Unravelling the genetics of inherited retinal dystrophies: Past, present and future. Prog Retin Eye Res 2017; 59:53-96. [PMID: 28363849 DOI: 10.1016/j.preteyeres.2017.03.003] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 03/21/2017] [Accepted: 03/23/2017] [Indexed: 02/07/2023]
Abstract
The identification of the genes underlying monogenic diseases has been of interest to clinicians and scientists for many years. Using inherited retinal dystrophies as an example of monogenic disease we describe the history of molecular genetic techniques that have been pivotal in the discovery of disease causing genes. The methods that were developed in the 1970's and 80's are still in use today but have been refined and improved. These techniques enabled the concept of the Human Genome Project to be envisaged and ultimately realised. When the successful conclusion of the project was announced in 2003 many new tools and, as importantly, many collaborations had been developed that facilitated a rapid identification of disease genes. In the post-human genome project era advances in computing power and the clever use of the properties of DNA replication has allowed the development of next-generation sequencing technologies. These methods have revolutionised the identification of disease genes because for the first time there is no need to define the position of the gene in the genome. The use of next generation sequencing in a diagnostic setting has allowed many more patients with an inherited retinal dystrophy to obtain a molecular diagnosis for their disease. The identification of novel genes that have a role in the development or maintenance of retinal function is opening up avenues of research which will lead to the development of new pharmacological and gene therapy approaches. Neither of which can be used unless the defective gene and protein is known. The continued development of sequencing technologies also holds great promise for the advent of truly personalised medicine.
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Affiliation(s)
- Suzanne Broadgate
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Jing Yu
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK
| | - Susan M Downes
- Oxford Eye Hospital, Oxford University Hospitals NHS Trust, Oxford, OX3 9DU, UK
| | - Stephanie Halford
- Nuffield Laboratory of Ophthalmology, Nuffield Department of Clinical Neurosciences, University of Oxford, Levels 5 and 6 West Wing, John Radcliffe Hospital, Headley Way, Oxford, OX3 9DU, UK.
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36
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Bosch Grau M, Masson C, Gadadhar S, Rocha C, Tort O, Marques Sousa P, Vacher S, Bieche I, Janke C. Alterations in the balance of tubulin glycylation and glutamylation in photoreceptors leads to retinal degeneration. J Cell Sci 2017; 130:938-949. [PMID: 28104815 DOI: 10.1242/jcs.199091] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 01/10/2017] [Indexed: 01/09/2023] Open
Abstract
Tubulin is subject to a wide variety of posttranslational modifications, which, as part of the tubulin code, are involved in the regulation of microtubule functions. Glycylation has so far predominantly been found in motile cilia and flagella, and absence of this modification leads to ciliary disassembly. Here, we demonstrate that the correct functioning of connecting cilia of photoreceptors, which are non-motile sensory cilia, is also dependent on glycylation. In contrast to many other tissues, only one glycylase, TTLL3, is expressed in retina. Ttll3-/- mice lack glycylation in photoreceptors, which results in shortening of connecting cilia and slow retinal degeneration. Moreover, absence of glycylation results in increased levels of tubulin glutamylation in photoreceptors, and inversely, the hyperglutamylation observed in the Purkinje cell degeneration (pcd) mouse abolishes glycylation. This suggests that both posttranslational modifications compete for modification sites, and that unbalancing the glutamylation-glycylation equilibrium on axonemes of connecting cilia, regardless of the enzymatic mechanism, invariably leads to retinal degeneration.
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Affiliation(s)
- Montserrat Bosch Grau
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Christel Masson
- CERTO Centre d'Etudes et de Recherches Thérapeutiques en Ophtalmologie, Université Paris Sud, Université Paris-Saclay, CNRS UMR9197, Orsay F-91405, France
| | - Sudarshan Gadadhar
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Cecilia Rocha
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Olivia Tort
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Patricia Marques Sousa
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France.,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
| | - Sophie Vacher
- Institut Curie, PSL Research University, Department of Genetics, Paris F-75005, France
| | - Ivan Bieche
- Institut Curie, PSL Research University, Department of Genetics, Paris F-75005, France.,Université Paris Descartes, Sorbonne Paris Cité, Paris F-75005, France
| | - Carsten Janke
- Institut Curie, PSL Research University, CNRS UMR3348, Orsay F-91405, France .,Université Paris Sud, Université Paris-Saclay, CNRS UMR3348, Orsay F-91405, France
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Coppieters F, Ascari G, Dannhausen K, Nikopoulos K, Peelman F, Karlstetter M, Xu M, Brachet C, Meunier I, Tsilimbaris M, Tsika C, Blazaki S, Vergult S, Farinelli P, Van Laethem T, Bauwens M, De Bruyne M, Chen R, Langmann T, Sui R, Meire F, Rivolta C, Hamel C, Leroy B, De Baere E. Isolated and Syndromic Retinal Dystrophy Caused by Biallelic Mutations in RCBTB1, a Gene Implicated in Ubiquitination. Am J Hum Genet 2016; 99:470-80. [PMID: 27486781 PMCID: PMC4974088 DOI: 10.1016/j.ajhg.2016.06.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2016] [Accepted: 06/20/2016] [Indexed: 11/24/2022] Open
Abstract
Inherited retinal dystrophies (iRDs) are a group of genetically and clinically heterogeneous conditions resulting from mutations in over 250 genes. Here, homozygosity mapping and whole-exome sequencing (WES) in a consanguineous family revealed a homozygous missense mutation, c.973C>T (p.His325Tyr), in RCBTB1. In affected individuals, it was found to segregate with retinitis pigmentosa (RP), goiter, primary ovarian insufficiency, and mild intellectual disability. Subsequent analysis of WES data in different cohorts uncovered four additional homozygous missense mutations in five unrelated families in whom iRD segregates with or without syndromic features. Ocular phenotypes ranged from typical RP starting in the second decade to chorioretinal dystrophy with a later age of onset. The five missense mutations affect highly conserved residues either in the sixth repeat of the RCC1 domain or in the BTB1 domain. A founder haplotype was identified for mutation c.919G>A (p.Val307Met), occurring in two families of Mediterranean origin. We showed ubiquitous mRNA expression of RCBTB1 and demonstrated predominant RCBTB1 localization in human inner retina. RCBTB1 was very recently shown to be involved in ubiquitination, more specifically as a CUL3 substrate adaptor. Therefore, the effect on different components of the CUL3 and NFE2L2 (NRF2) pathway was assessed in affected individuals’ lymphocytes, revealing decreased mRNA expression of NFE2L2 and several NFE2L2 target genes. In conclusion, our study puts forward mutations in RCBTB1 as a cause of autosomal-recessive non-syndromic and syndromic iRD. Finally, our data support a role for impaired ubiquitination in the pathogenetic mechanism of RCBTB1 mutations.
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38
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FAM161A and TTC8 are Differentially Expressed in Non-Allelelic Early Onset Retinal Degeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 854:201-7. [PMID: 26427412 DOI: 10.1007/978-3-319-17121-0_27] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Ciliary genes FAM161A and TTC8 have been implicated in retinal degeneration (RD) in humans and in dogs. The identification of FAM161A and TTC8 mutations in canine RD is exciting as there is the potential to develop novel large animal models for RD. However, the disease phenotypes in the dog and the roles of abnormal genes in disease pathology have yet to be fully characterized. The present study evaluated the expression patterns of FAM161A and TTC8 during normal retinal development in dogs, and in three non-allelic, early onset canine RD models at critical time points of the disease: RCD1, XLPRA2 and ERD. Both genes were differentially expressed in RCD1 and ERD, but not in XLPRA2. These results add evidence to the hypothesis that (a) mutations in many retinal genes have a cascade effect on the expression of multiple, possibly unrelated genes and (b) a large number and wide range of genes probably contribute to RD in general.
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Whole-exome sequencing reveals a novel frameshift mutation in the FAM161A gene causing autosomal recessive retinitis pigmentosa in the Indian population. J Hum Genet 2015; 60:625-30. [PMID: 26246154 DOI: 10.1038/jhg.2015.92] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Revised: 06/18/2015] [Accepted: 06/30/2015] [Indexed: 11/08/2022]
Abstract
Retinitis pigmentosa (RP) is a heterogenous group of inherited retinal degenerations caused by mutations in at least 50 genes. To identify genetic mutations underlying autosomal recessive RP (arRP), we performed whole-exome sequencing study on two consanguineous marriage Indian families (RP-252 and RP-182) and 100 sporadic RP patients. Here we reported novel mutation in FAM161A in RP-252 and RP-182 with two patients affected with RP in each family. The FAM161A gene was identified as the causative gene for RP28, an autosomal recessive form of RP. By whole-exome sequencing we identified several homozygous genomic regions, one of which included the recently identified FAM161A gene mutated in RP28-linked arRP. Sequencing analysis revealed the presence of a novel homozygous frameshift mutation p.R592FsX2 in both patients of family RP-252 and family RP-182. In 100 sporadic Indian RP patients, this novel homozygous frameshift mutation p.R592FsX2 was identified in one sporadic patient ARRP-S-I-46 by whole-exome sequencing and validated by Sanger sequencing. Meanwhile, this homozygous frameshift mutation was absent in 1000 ethnicity-matched control samples screened by direct Sanger sequencing. In conclusion, we identified a novel homozygous frameshift mutations of RP28-linked RP gene FAM161A in Indian population.
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40
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Diverse clinical phenotypes associated with a nonsense mutation in FAM161A. Eye (Lond) 2015; 29:1226-32. [PMID: 26113502 DOI: 10.1038/eye.2015.93] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 04/09/2015] [Indexed: 12/12/2022] Open
Abstract
PURPOSE Mutations in the FAM161A gene have been reported in association with autosomal recessive retinitis pigmentosa (arRP) in several ethnic populations. This study aimed to assess the prevalence of FAM161A-related retinopathy in a British cohort and to characterise the phenotype associated with mutations in this gene. METHODS The FAM161A coding region and intron-exon boundaries were screened by Sanger sequencing in 120 retinitis pigmentosa (RP) patients (with likely autosomal recessive inheritance) in whom mutations in other known major RP genes have been ruled out by commercially available testing. Homozygosity mapping was performed in one consanguineous family, and high-throughput sequencing of candidate genes was performed to identify disease-associated changes. Clinical assessment of affected individuals included perimetry testing, fundus autofluorescence imaging, and optical coherence tomography. RESULTS Two patients of British origin with a homozygous mutation in FAM161A (c.1309A>T, p.Arg437*) were identified by Sanger sequencing. Homozygosity mapping and subsequent high-throughput sequencing analysis identified a further family of Pakistani origin with the same genotype. Clinical examination of affected members of these families revealed that this mutation was associated with a diverse clinical phenotype, ranging from mild disease with preservation of central acuity to severe visual impairment. CONCLUSIONS Homozygosity for the c.1309A>T, p.Arg437* variant in FAM161A is a relatively common cause of arRP. The mutation occurs in diverse ethnic populations, associated with typical retinitis pigmentosa with disease onset usually in the second or third decade of life.
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41
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Aslanidis A, Karlstetter M, Scholz R, Fauser S, Neumann H, Fried C, Pietsch M, Langmann T. Activated microglia/macrophage whey acidic protein (AMWAP) inhibits NFκB signaling and induces a neuroprotective phenotype in microglia. J Neuroinflammation 2015; 12:77. [PMID: 25928566 PMCID: PMC4417279 DOI: 10.1186/s12974-015-0296-6] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2014] [Accepted: 04/07/2015] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Microglia reactivity is a hallmark of neurodegenerative diseases. We have previously identified activated microglia/macrophage whey acidic protein (AMWAP) as a counter-regulator of pro-inflammatory response. Here, we studied its mechanisms of action with a focus on toll-like receptor (TLR) and nuclear factor κB (NFκB) signaling. METHODS Recombinant AMWAP was produced in Escherichia coli and HEK293 EBNA cells and purified by affinity chromatography. AMWAP uptake was identified by fluorescent labeling, and pro-inflammatory microglia markers were measured by qRT-PCR after stimulation with TLR ligands. NFκB pathway proteins were assessed by immunocytochemistry, Western blot, and immunoprecipitation. A 20S proteasome activity assay was used to investigate the anti-peptidase activity of AMWAP. Microglial neurotoxicity was estimated by nitrite measurement and quantification of caspase 3/7 levels in 661W photoreceptors cultured in the presence of microglia-conditioned medium. Microglial proliferation was investigated using flow cytometry, and their phagocytosis was monitored by the uptake of 661W photoreceptor debris. RESULTS AMWAP was secreted from lipopolysaccharide (LPS)-activated microglia and recombinant AMWAP reduced gene transcription of IL6, iNOS, CCL2, CASP11, and TNFα in BV-2 microglia treated with LPS as TLR4 ligand. This effect was replicated with murine embryonic stem cell-derived microglia (ESdM) and primary brain microglia. AMWAP also diminished pro-inflammatory markers in microglia activated with the TLR2 ligand zymosan but had no effects on IL6, iNOS, and CCL2 transcription in cells treated with CpG oligodeoxynucleotides as TLR9 ligand. Microglial uptake of AMWAP effectively inhibited TLR4-dependent NFκB activation by preventing IRAK-1 and IκBα proteolysis. No inhibition of IκBα phosphorylation or ubiquitination and no influence on overall 20S proteasome activity were observed. Functionally, both microglial nitric oxide (NO) secretion and 661W photoreceptor apoptosis were significantly reduced after AMWAP treatment. AMWAP promoted the filopodia formation of microglia and increased the phagocytic uptake of apoptotic 661W photoreceptor cells. CONCLUSIONS AMWAP is secreted from reactive microglia and acts in a paracrine fashion to counter-balance TLR2/TLR4-induced reactivity through NFκB inhibition. AMWAP also induces a neuroprotective microglial phenotype with reduced neurotoxicity and increased phagocytosis. We therefore hypothesize that anti-inflammatory whey acidic proteins could have a therapeutic potential in neurodegenerative diseases of the brain and the retina.
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Affiliation(s)
- Alexander Aslanidis
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Kerpener Strasse 62, D-50931, Cologne, Germany.
| | - Marcus Karlstetter
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Kerpener Strasse 62, D-50931, Cologne, Germany.
| | - Rebecca Scholz
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Kerpener Strasse 62, D-50931, Cologne, Germany.
| | - Sascha Fauser
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Kerpener Strasse 62, D-50931, Cologne, Germany.
| | - Harald Neumann
- Institute of Reconstructive Neurobiology, University of Bonn, Sigmund-Freud-Straße 25, D-53127, Bonn, Germany.
| | - Cora Fried
- Department of Pharmacology, University of Cologne, Gleueler Straße 24, D-50931, Cologne, Germany.
| | - Markus Pietsch
- Department of Pharmacology, University of Cologne, Gleueler Straße 24, D-50931, Cologne, Germany.
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Kerpener Strasse 62, D-50931, Cologne, Germany.
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Di Gioia SA, Farinelli P, Letteboer SJF, Arsenijevic Y, Sharon D, Roepman R, Rivolta C. Interactome analysis reveals that FAM161A, deficient in recessive retinitis pigmentosa, is a component of the Golgi-centrosomal network. Hum Mol Genet 2015; 24:3359-71. [PMID: 25749990 DOI: 10.1093/hmg/ddv085] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 03/04/2015] [Indexed: 11/13/2022] Open
Abstract
Defects in FAM161A, a protein of unknown function localized at the cilium of retinal photoreceptor cells, cause retinitis pigmentosa, a form of hereditary blindness. By using different fragments of this protein as baits to screen cDNA libraries of human and bovine retinas, we defined a yeast two-hybrid-based FAM161A interactome, identifying 53 bona fide partners. In addition to statistically significant enrichment in ciliary proteins, as expected, this interactome revealed a substantial bias towards proteins from the Golgi apparatus, the centrosome and the microtubule network. Validation of interaction with key partners by co-immunoprecipitation and proximity ligation assay confirmed that FAM161A is a member of the recently recognized Golgi-centrosomal interactome, a network of proteins interconnecting Golgi maintenance, intracellular transport and centrosome organization. Notable FAM161A interactors included AKAP9, FIP3, GOLGA3, KIFC3, KLC2, PDE4DIP, NIN and TRIP11. Furthermore, analysis of FAM161A localization during the cell cycle revealed that this protein followed the centrosome during all stages of mitosis, likely reflecting a specific compartmentalization related to its role at the ciliary basal body during the G0 phase. Altogether, these findings suggest that FAM161A's activities are probably not limited to ciliary tasks but also extend to more general cellular functions, highlighting possible novel mechanisms for the molecular pathology of retinal disease.
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Affiliation(s)
| | - Pietro Farinelli
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland
| | - Stef J F Letteboer
- Department of Human Genetics and Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands and
| | - Yvan Arsenijevic
- Unit of Gene Therapy and Stem Cell Biology, Jules-Gonin Eye Hospital, University of Lausanne, Lausanne, Switzerland
| | - Dror Sharon
- Department of Ophthalmology, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Ronald Roepman
- Department of Human Genetics and Nijmegen Centre for Molecular Life Sciences, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands and
| | - Carlo Rivolta
- Department of Medical Genetics, University of Lausanne, Lausanne, Switzerland
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Kevany BM, Zhang N, Jastrzebska B, Palczewski K. Animals deficient in C2Orf71, an autosomal recessive retinitis pigmentosa-associated locus, develop severe early-onset retinal degeneration. Hum Mol Genet 2015; 24:2627-40. [PMID: 25616964 DOI: 10.1093/hmg/ddv025] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2014] [Accepted: 01/21/2015] [Indexed: 02/01/2023] Open
Abstract
Genetic mapping was recently used to identify the underlying cause for a previously uncharacterized cohort of autosomal recessive retinitis pigmentosa cases. Genetic mapping of affected individuals resulted in the identification of an uncharacterized gene, C2Orf71, as the causative locus. However, initial homology searches failed to reveal similarities to any previously characterized protein or domain. To address this issue, we characterized the mouse homolog, BC027072. Immunohistochemistry with a custom polyclonal antibody showed staining localized to the inner segments (IS) of photoreceptor cells, as well as the outer segments (OS) of cone cells. A knockout mouse line (BC(-/-)) was generated and demonstrated that loss of this gene results in a severe, early-onset retinal degeneration. Histology and electron microscopy (EM) revealed disorganized OS as early as 3 weeks with complete loss by 24 weeks of age. EM micrographs displayed packets of cellular material containing OS discs or IS organelles in the OS region and abnormal retinal pigmented epithelium cells. Analyses of retinoids and rhodopsin levels showed <20% in BC(-/-) versus wild-type mice early in development. Electroretinograms demonstrated that affected mice were virtually non-responsive to light by 8 weeks of age. Lastly, RNAseq analysis of ocular gene expression in BC(-/-) mice revealed clues to the causes of the progressive retinal degenerations. Although its function remains unknown, this protein appears essential for normal OS development/maintenance and vision in humans and mice. RNAseq data are available in the GEO database under accession: GSE63810.
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Affiliation(s)
- Brian M Kevany
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Ning Zhang
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Beata Jastrzebska
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Krzysztof Palczewski
- Department of Pharmacology, Cleveland Center for Membrane and Structural Biology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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Karlstetter M, Scholz R, Rutar M, Wong WT, Provis JM, Langmann T. Retinal microglia: just bystander or target for therapy? Prog Retin Eye Res 2014; 45:30-57. [PMID: 25476242 DOI: 10.1016/j.preteyeres.2014.11.004] [Citation(s) in RCA: 374] [Impact Index Per Article: 37.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2014] [Revised: 11/20/2014] [Accepted: 11/25/2014] [Indexed: 10/24/2022]
Abstract
Resident microglial cells can be regarded as the immunological watchdogs of the brain and the retina. They are active sensors of their neuronal microenvironment and rapidly respond to various insults with a morphological and functional transformation into reactive phagocytes. There is strong evidence from animal models and in situ analyses of human tissue that microglial reactivity is a common hallmark of various retinal degenerative and inflammatory diseases. These include rare hereditary retinopathies such as retinitis pigmentosa and X-linked juvenile retinoschisis but also comprise more common multifactorial retinal diseases such as age-related macular degeneration, diabetic retinopathy, glaucoma, and uveitis as well as neurological disorders with ocular manifestation. In this review, we describe how microglial function is kept in balance under normal conditions by cross-talk with other retinal cells and summarize how microglia respond to different forms of retinal injury. In addition, we present the concept that microglia play a key role in local regulation of complement in the retina and specify aspects of microglial aging relevant for chronic inflammatory processes in the retina. We conclude that this resident immune cell of the retina cannot be simply regarded as bystander of disease but may instead be a potential therapeutic target to be modulated in the treatment of degenerative and inflammatory diseases of the retina.
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Affiliation(s)
- Marcus Karlstetter
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Rebecca Scholz
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany
| | - Matt Rutar
- The John Curtin School of Medical Research, The Australian National University (ANU), Canberra, Australian Capital Territory, Australia
| | - Wai T Wong
- Unit on Neuron-Glia Interactions in Retinal Disease, National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Jan M Provis
- The John Curtin School of Medical Research, The Australian National University (ANU), Canberra, Australian Capital Territory, Australia
| | - Thomas Langmann
- Laboratory for Experimental Immunology of the Eye, Department of Ophthalmology, University of Cologne, Cologne, Germany.
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Beck BB, Phillips JB, Bartram MP, Wegner J, Thoenes M, Pannes A, Sampson J, Heller R, Göbel H, Koerber F, Neugebauer A, Hedergott A, Nürnberg G, Nürnberg P, Thiele H, Altmüller J, Toliat MR, Staubach S, Boycott KM, Valente EM, Janecke AR, Eisenberger T, Bergmann C, Tebbe L, Wang Y, Wu Y, Fry AM, Westerfield M, Wolfrum U, Bolz HJ. Mutation of POC1B in a severe syndromic retinal ciliopathy. Hum Mutat 2014; 35:1153-62. [PMID: 25044745 PMCID: PMC4425427 DOI: 10.1002/humu.22618] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 07/12/2014] [Indexed: 12/20/2022]
Abstract
We describe a consanguineous Iraqi family with Leber congenital amaurosis (LCA), Joubert syndrome (JBTS), and polycystic kidney disease (PKD). Targeted next-generation sequencing for excluding mutations in known LCA and JBTS genes, homozygosity mapping, and whole-exome sequencing identified a homozygous missense variant, c.317G>C (p.Arg106Pro), in POC1B, a gene essential for ciliogenesis, basal body, and centrosome integrity. In silico modeling suggested a requirement of p.Arg106 for the formation of the third WD40 repeat and a protein interaction interface. In human and mouse retina, POC1B localized to the basal body and centriole adjacent to the connecting cilium of photoreceptors and in synapses of the outer plexiform layer. Knockdown of Poc1b in zebrafish caused cystic kidneys and retinal degeneration with shortened and reduced photoreceptor connecting cilia, compatible with the human syndromic ciliopathy. A recent study describes homozygosity for p.Arg106ProPOC1B in a family with nonsyndromic cone-rod dystrophy. The phenotype associated with homozygous p.Arg106ProPOC1B may thus be highly variable, analogous to homozygous p.Leu710Ser in WDR19 causing either isolated retinitis pigmentosa or Jeune syndrome. Our study indicates that POC1B is required for retinal integrity, and we propose POC1B mutations as a probable cause for JBTS with severe PKD.
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Affiliation(s)
- Bodo B. Beck
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany
| | | | - Malte P. Bartram
- Department II of Internal Medicine and Center for Molecular Medicine Cologne, University Hospital of Cologne, 50931 Cologne, Germany
| | - Jeremy Wegner
- Institute of Neuroscience, University of Oregon, 97401 Eugene, Oregon, USA
| | - Michaela Thoenes
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany
| | - Andrea Pannes
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany
| | - Josephina Sampson
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom, LE7 9HN
| | - Raoul Heller
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany
| | - Heike Göbel
- Department of Pathology, University Hospital of Cologne, 50931 Cologne, Germany
| | - Friederike Koerber
- Department of Radiology, University Hospital of Cologne, 50931 Cologne, Germany
| | - Antje Neugebauer
- Department of Ophthalmology, University Hospital of Cologne, 50931 Cologne, Germany
| | - Andrea Hedergott
- Department of Ophthalmology, University Hospital of Cologne, 50931 Cologne, Germany
| | - Gudrun Nürnberg
- Cologne Center for Genomics (CCG) and Centre for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Peter Nürnberg
- Cologne Center for Genomics (CCG) and Centre for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
- Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, 50931 Cologne, Germany
| | - Holger Thiele
- Cologne Center for Genomics (CCG) and Centre for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Janine Altmüller
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany
- Cologne Center for Genomics (CCG) and Centre for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Mohammad R. Toliat
- Cologne Center for Genomics (CCG) and Centre for Molecular Medicine Cologne (CMMC), University of Cologne, 50931 Cologne, Germany
| | - Simon Staubach
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany
| | - Kym M. Boycott
- Children’s Hospital of Eastern Ontario Research Institute, University of Ottawa, K1H 8L1 Ottawa, Canada
| | - Enza Maria Valente
- Mendel Laboratory, IRCCS Casa Sollievo della Sofferenza Institute, 71013 San Giovanni Rotondo, Italy
- Department of Medicine and Surgery, University of Salerno, 84080 Salerno, Italy
| | - Andreas R. Janecke
- Department of Pediatrics I, and Division of Human Genetics, Innsbruck Medical University, 6020 Innsbruck, Austria
| | | | - Carsten Bergmann
- Center for Human Genetics, Bioscientia, 55218 Ingelheim, Germany
- Department of Medicine, Renal Division, University of Freiburg Medical Center, 79095 Freiburg, Germany
| | - Lars Tebbe
- Department of Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg, University of Mainz, 55099 Mainz, Germany
| | - Yang Wang
- Lab of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, 518000 Shenzhen, P. R. China
| | - Yundong Wu
- Lab of Computational Chemistry and Drug Design, Laboratory of Chemical Genomics, Peking University Shenzhen Graduate School, 518000 Shenzhen, P. R. China
- College of Chemistry, Peking University, 100871 Beijing, P. R. China
| | - Andrew M. Fry
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom, LE7 9HN
| | - Monte Westerfield
- Institute of Neuroscience, University of Oregon, 97401 Eugene, Oregon, USA
| | - Uwe Wolfrum
- Department of Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg, University of Mainz, 55099 Mainz, Germany
- Focus Program Translational Neurosciences (FTN), Johannes Gutenberg University of Mainz, 55122 Mainz, Germany
| | - Hanno J. Bolz
- Institute of Human Genetics, University Hospital of Cologne, 50931 Cologne, Germany
- Center for Human Genetics, Bioscientia, 55218 Ingelheim, Germany
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