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Takahashi K, Sudharsan R, Beltran WA. Mapping protein distribution in the canine photoreceptor sensory cilium and calyceal processes by ultrastructure expansion microscopy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.27.600953. [PMID: 38979372 PMCID: PMC11230445 DOI: 10.1101/2024.06.27.600953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Photoreceptors are highly polarized sensory neurons, possessing a unique ciliary structure known as the photoreceptor sensory cilium (PSC). Vertebrates have two subtypes of photoreceptors: rods, which are responsible for night vision, and cones, which support daylight vision and color perception. Despite identifying functional and morphological differences between these subtypes, ultrastructural analyses of the PSC molecular architecture in rods and cones are still lacking. In this study, we employed ultrastructure expansion microscopy (U-ExM) to characterize the molecular architecture of the PSC in canine retina. We demonstrated that U-ExM is applicable to both non-frozen and cryopreserved retinal tissues with standard paraformaldehyde fixation. Using this validated U-ExM protocol, we revealed the molecular localization of numerous ciliopathy-related proteins in canine photoreceptors. Furthermore, we identified significant architectural differences in the PSC, ciliary rootlet, and calyceal processes between canine rods and cones. These findings pave the way for a better understanding of alterations in the molecular architecture of the PSC in canine models of retinal ciliopathies.
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Kruczek K, Swaroop A. Patient stem cell-derived in vitro disease models for developing novel therapies of retinal ciliopathies. Curr Top Dev Biol 2023; 155:127-163. [PMID: 38043950 DOI: 10.1016/bs.ctdb.2023.09.003] [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] [Indexed: 12/05/2023]
Abstract
Primary cilia are specialized organelles on the surface of almost all cells in vertebrate tissues and are primarily involved in the detection of extracellular stimuli. In retinal photoreceptors, cilia are uniquely modified to form outer segments containing components required for the detection of light in stacks of membrane discs. Not surprisingly, vision impairment is a frequent phenotype associated with ciliopathies, a heterogeneous class of conditions caused by mutations in proteins required for formation, maintenance and/or function of primary cilia. Traditionally, immortalized cell lines and model organisms have been used to provide insights into the biology of ciliopathies. The advent of methods for reprogramming human somatic cells into pluripotent stem cells has enabled the generation of in vitro disease models directly from patients suffering from ciliopathies. Such models help us in investigating pathological mechanisms specific to human physiology and in developing novel therapeutic approaches. In this article, we review current protocols to differentiate human pluripotent stem cells into retinal cell types, and discuss how these cellular and/or organoid models can be utilized to interrogate pathobiology of ciliopathies affecting the retina and for testing prospective treatments.
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Affiliation(s)
- Kamil Kruczek
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, United States.
| | - Anand Swaroop
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, Bethesda, MD, United States.
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Birkhead M, Otido S, Mabaso T, Mopeli K, Tlhapi D, Verwey C, Dangor Z. Ultrastructure for the diagnosis of primary ciliary dyskinesia in South Africa, a resource-limited setting. Front Pediatr 2023; 11:1247638. [PMID: 37645034 PMCID: PMC10461090 DOI: 10.3389/fped.2023.1247638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2023] [Accepted: 08/04/2023] [Indexed: 08/31/2023] Open
Abstract
Introduction International guidelines recommend a multi-faceted approach for successful diagnoses of primary ciliary dyskinesia (PCD). In the absence of a gold standard test, a combination of genetic testing/microscopic analysis of structure and function/nasal nitric oxide measurement is used. In resource-limited settings, often none of the above tests are available, and in South Africa, only transmission electron microscopy (TEM) is available in central anatomical pathology departments. The aim of this study was to describe the clinical and ultrastructural findings of suspected PCD cases managed by pediatric pulmonologists at a tertiary-level state funded hospital in Johannesburg. Methods Nasal brushings were taken from 14 children with chronic respiratory symptoms in keeping with a PCD phenotype. Ultrastructural analysis in accordance with the international consensus guidelines for TEM-PCD diagnostic reporting was undertaken. Results TEM observations confirmed 43% (6) of the clinically-suspected cases (hallmark ultrastructural defects in the dynein arms of the outer doublets), whilst 57% (8) required another PCD testing modality to support ultrastructural observations. Of these, 25% (2) had neither ultrastructural defects nor did they present with bronchiectasis. Of the remaining cases, 83% (5) had very few ciliated cells (all of which were sparsely ciliated), together with goblet cell hyperplasia. There was the apparent absence of ciliary rootlets in 17% (1) case. Discussion In resource-limited settings in which TEM is the only available testing modality, confirmatory and probable diagnoses of PCD can be made to facilitate early initiation of treatment of children with chronic respiratory symptoms.
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Affiliation(s)
- Monica Birkhead
- Centre for Emerging Zoonotic and Parasitic Diseases, National Institute for Communicable Diseases – a Division of the National Health Laboratory Service, Johannesburg, South Africa
| | - Samuel Otido
- Department of Paediatrics and Child Health, Aga Khan University Hospital, Nairobi, Kenya
| | - Theodore Mabaso
- Department of Paediatrics and Child Health, Faculty of Health Sciences, Chris Hani Baragwanath Academic Hospital, University of the Witwatersrand, Johannesburg, South Africa
| | - Keketso Mopeli
- Department of Paediatrics and Child Health, Faculty of Health Sciences, Chris Hani Baragwanath Academic Hospital, University of the Witwatersrand, Johannesburg, South Africa
| | - Dorcas Tlhapi
- Department of Paediatrics and Child Health, Faculty of Health Sciences, Chris Hani Baragwanath Academic Hospital, University of the Witwatersrand, Johannesburg, South Africa
| | - Charl Verwey
- Department of Paediatrics and Child Health, Faculty of Health Sciences, Chris Hani Baragwanath Academic Hospital, University of the Witwatersrand, Johannesburg, South Africa
- Medical Research Council: Vaccines and Infectious Diseases Analytics Research Unit, University of the Witwatersrand, Johannesburg, South Africa
| | - Ziyaad Dangor
- Department of Paediatrics and Child Health, Faculty of Health Sciences, Chris Hani Baragwanath Academic Hospital, University of the Witwatersrand, Johannesburg, South Africa
- Medical Research Council: Vaccines and Infectious Diseases Analytics Research Unit, University of the Witwatersrand, Johannesburg, South Africa
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Packard M, Gilbert MC, Tetrault E, Albertson RC. Zebrafish crocc2 mutants exhibit divergent craniofacial shape, misregulated variability, and aberrant cartilage morphogenesis. Dev Dyn 2023; 252:1026-1045. [PMID: 37032317 PMCID: PMC10524572 DOI: 10.1002/dvdy.591] [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: 11/07/2022] [Revised: 03/21/2023] [Accepted: 03/29/2023] [Indexed: 04/11/2023] Open
Abstract
BACKGROUND Phenotypic variation is of paramount importance in development, evolution, and human health; however, the molecular mechanisms that influence organ shape and shape variability are not well understood. During craniofacial development, the behavior of skeletal precursors is regulated by both biochemical and environmental inputs, and the primary cilia play critical roles in transducing both types of signals. Here, we examine a gene that encodes a key constituent of the ciliary rootlets, crocc2, and its role in cartilage morphogenesis in larval zebrafish. RESULTS Geometric morphometric analysis of crocc2 mutants revealed altered craniofacial shapes and expanded variation. At the cellular level, we observed altered chondrocyte shapes and planar cell polarity across multiple stages in crocc2 mutants. Notably, cellular defects were specific to areas that experience direct mechanical input. Cartilage cell number, apoptosis, and bone patterning were not affected in crocc2 mutants. CONCLUSIONS Whereas "regulatory" genes are widely implicated in patterning the craniofacial skeleton, genes that encode "structural" aspects of the cell are increasingly implicated in shaping the face. Our results add crocc2 to this list, and demonstrate that it affects craniofacial geometry and canalizes phenotypic variation. We propose that it does so via mechanosensing, possibly through the ciliary rootlet. If true, this would implicate a new organelle in skeletal development and evolution.
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Affiliation(s)
- Mary Packard
- Department of Biology, University of Massachusetts, Amherst, MA 01003, U.S.A
| | - Michelle C. Gilbert
- Organismic and Evolutionary Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, U.S.A
- Current address, Department of Biology, Penn State University, University Park, PA 16802, U.S.A
| | - Emily Tetrault
- Molecular and Cellular Biology Graduate Program, University of Massachusetts, Amherst, MA 01003, U.S.A
| | - R. Craig Albertson
- Department of Biology, University of Massachusetts, Amherst, MA 01003, U.S.A
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Aryal S, Anand D, Huang H, Reddy AP, Wilmarth PA, David LL, Lachke SA. Proteomic profiling of retina and retinal pigment epithelium combined embryonic tissue to facilitate ocular disease gene discovery. Hum Genet 2023; 142:927-947. [PMID: 37191732 PMCID: PMC10680127 DOI: 10.1007/s00439-023-02570-0] [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: 03/03/2023] [Accepted: 05/04/2023] [Indexed: 05/17/2023]
Abstract
To expedite gene discovery in eye development and its associated defects, we previously developed a bioinformatics resource-tool iSyTE (integrated Systems Tool for Eye gene discovery). However, iSyTE is presently limited to lens tissue and is predominantly based on transcriptomics datasets. Therefore, to extend iSyTE to other eye tissues on the proteome level, we performed high-throughput tandem mass spectrometry (MS/MS) on mouse embryonic day (E)14.5 retina and retinal pigment epithelium combined tissue and identified an average of 3300 proteins per sample (n = 5). High-throughput expression profiling-based gene discovery approaches-involving either transcriptomics or proteomics-pose a key challenge of prioritizing candidates from thousands of RNA/proteins expressed. To address this, we used MS/MS proteome data from mouse whole embryonic body (WB) as a reference dataset and performed comparative analysis-termed "in silico WB-subtraction"-with the retina proteome dataset. In silico WB-subtraction identified 90 high-priority proteins with retina-enriched expression at stringency criteria of ≥ 2.5 average spectral counts, ≥ 2.0 fold-enrichment, false discovery rate < 0.01. These top candidates represent a pool of retina-enriched proteins, several of which are associated with retinal biology and/or defects (e.g., Aldh1a1, Ank2, Ank3, Dcn, Dync2h1, Egfr, Ephb2, Fbln5, Fbn2, Hras, Igf2bp1, Msi1, Rbp1, Rlbp1, Tenm3, Yap1, etc.), indicating the effectiveness of this approach. Importantly, in silico WB-subtraction also identified several new high-priority candidates with potential regulatory function in retina development. Finally, proteins exhibiting expression or enriched-expression in the retina are made accessible in a user-friendly manner at iSyTE ( https://research.bioinformatics.udel.edu/iSyTE/ ), to allow effective visualization of this information and facilitate eye gene discovery.
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Affiliation(s)
- Sandeep Aryal
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA
| | - Hongzhan Huang
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, 19713, USA
| | - Ashok P Reddy
- Proteomics Shared Resource, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Phillip A Wilmarth
- Proteomics Shared Resource, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Larry L David
- Proteomics Shared Resource, Oregon Health and Science University, Portland, OR, 97239, USA
- Department of Chemical Physiology and Biochemistry, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Salil A Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE, 19716, USA.
- Center for Bioinformatics and Computational Biology, University of Delaware, Newark, DE, 19713, USA.
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6
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Aryal S, Anand D, Huang H, Reddy AP, Wilmarth PA, David LL, Lachke SA. Proteomic profiling of retina and retinal pigment epithelium combined embryonic tissue to facilitate ocular disease gene discovery. RESEARCH SQUARE 2023:rs.3.rs-2652395. [PMID: 36993571 PMCID: PMC10055508 DOI: 10.21203/rs.3.rs-2652395/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
To expedite gene discovery in eye development and its associated defects, we previously developed a bioinformatics resource-tool iSyTE (integrated Systems Tool for Eye gene discovery). However, iSyTE is presently limited to lens tissue and is predominantly based on transcriptomics datasets. Therefore, to extend iSyTE to other eye tissues on the proteome level, we performed high-throughput tandem mass spectrometry (MS/MS) on mouse embryonic day (E)14.5 retina and retinal pigment epithelium combined tissue and identified an average of 3,300 proteins per sample (n=5). High-throughput expression profiling-based gene discovery approaches-involving either transcriptomics or proteomics-pose a key challenge of prioritizing candidates from thousands of RNA/proteins expressed. To address this, we used MS/MS proteome data from mouse whole embryonic body (WB) as a reference dataset and performed comparative analysis-termed "in silico WB-subtraction"-with the retina proteome dataset. In silico WB-subtraction identified 90 high-priority proteins with retina-enriched expression at stringency criteria of ³2.5 average spectral counts, ³2.0 fold-enrichment, False Discovery Rate <0.01. These top candidates represent a pool of retina-enriched proteins, several of which are associated with retinal biology and/or defects (e.g., Aldh1a1, Ank2, Ank3, Dcn, Dync2h1, Egfr, Ephb2, Fbln5, Fbn2, Hras, Igf2bp1, Msi1, Rbp1, Rlbp1, Tenm3, Yap1, etc.), indicating the effectiveness of this approach. Importantly, in silico WB-subtraction also identified several new high-priority candidates with potential regulatory function in retina development. Finally, proteins exhibiting expression or enriched-expression in the retina are made accessible in a user-friendly manner at iSyTE (https://research.bioinformatics.udel.edu/iSyTE/), to allow effective visualization of this information and facilitate eye gene discovery.
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Affiliation(s)
- Sandeep Aryal
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA
| | - Deepti Anand
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA
| | - Hongzhan Huang
- Center for Bioinformatics & Computational Biology, University of Delaware, Newark, DE 19713 USA
| | - Ashok P. Reddy
- Proteomics Shared Resource, Oregon Health & Science University, Portland, OR 97239, USA
| | - Phillip A. Wilmarth
- Proteomics Shared Resource, Oregon Health & Science University, Portland, OR 97239, USA
| | - Larry L. David
- Proteomics Shared Resource, Oregon Health & Science University, Portland, OR 97239, USA
- Department of Chemical Physiology & Biochemistry, Oregon Health & Science University, Portland, OR 97239, USA
| | - Salil A. Lachke
- Department of Biological Sciences, University of Delaware, Newark, DE 19716 USA
- Center for Bioinformatics & Computational Biology, University of Delaware, Newark, DE 19713 USA
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Van Heurck R, Bonnefont J, Wojno M, Suzuki IK, Velez-Bravo FD, Erkol E, Nguyen DT, Herpoel A, Bilheu A, Beckers S, Ledent C, Vanderhaeghen P. CROCCP2 acts as a human-specific modifier of cilia dynamics and mTOR signaling to promote expansion of cortical progenitors. Neuron 2023; 111:65-80.e6. [PMID: 36334595 PMCID: PMC9831670 DOI: 10.1016/j.neuron.2022.10.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 08/12/2022] [Accepted: 10/09/2022] [Indexed: 11/06/2022]
Abstract
The primary cilium is a central signaling component during embryonic development. Here we focus on CROCCP2, a hominid-specific gene duplicate from ciliary rootlet coiled coil (CROCC), also known as rootletin, that encodes the major component of the ciliary rootlet. We find that CROCCP2 is highly expressed in the human fetal brain and not in other primate species. CROCCP2 gain of function in the mouse embryonic cortex and human cortical cells and organoids results in decreased ciliogenesis and increased cortical progenitor amplification, particularly basal progenitors. CROCCP2 decreases ciliary dynamics by inhibition of the IFT20 ciliary trafficking protein, which then impacts neurogenesis through increased mTOR signaling. Loss of function of CROCCP2 in human cortical cells and organoids leads to increased ciliogenesis, decreased mTOR signaling, and impaired basal progenitor amplification. These data identify CROCCP2 as a human-specific modifier of cortical neurogenesis that acts through modulation of ciliary dynamics and mTOR signaling.
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Affiliation(s)
- Roxane Van Heurck
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium,Department of Neurosciences, Leuven Brain Institute, KU Leuven, 3000 Leuven, Belgium,Université Libre de Bruxelles (U.L.B.), Institut de Recherches en Biologie Humaine et Moléculaire (IRIBHM), and ULB Neuroscience Institute (UNI), 1070 Brussels, Belgium
| | - Jérôme Bonnefont
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium,Department of Neurosciences, Leuven Brain Institute, KU Leuven, 3000 Leuven, Belgium,Université Libre de Bruxelles (U.L.B.), Institut de Recherches en Biologie Humaine et Moléculaire (IRIBHM), and ULB Neuroscience Institute (UNI), 1070 Brussels, Belgium
| | - Marta Wojno
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium,Department of Neurosciences, Leuven Brain Institute, KU Leuven, 3000 Leuven, Belgium,Université Libre de Bruxelles (U.L.B.), Institut de Recherches en Biologie Humaine et Moléculaire (IRIBHM), and ULB Neuroscience Institute (UNI), 1070 Brussels, Belgium
| | - Ikuo K. Suzuki
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium,Department of Neurosciences, Leuven Brain Institute, KU Leuven, 3000 Leuven, Belgium,Université Libre de Bruxelles (U.L.B.), Institut de Recherches en Biologie Humaine et Moléculaire (IRIBHM), and ULB Neuroscience Institute (UNI), 1070 Brussels, Belgium,Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
| | - Fausto D. Velez-Bravo
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium,Department of Neurosciences, Leuven Brain Institute, KU Leuven, 3000 Leuven, Belgium,Université Libre de Bruxelles (U.L.B.), Institut de Recherches en Biologie Humaine et Moléculaire (IRIBHM), and ULB Neuroscience Institute (UNI), 1070 Brussels, Belgium
| | - Emir Erkol
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium,Department of Neurosciences, Leuven Brain Institute, KU Leuven, 3000 Leuven, Belgium,Université Libre de Bruxelles (U.L.B.), Institut de Recherches en Biologie Humaine et Moléculaire (IRIBHM), and ULB Neuroscience Institute (UNI), 1070 Brussels, Belgium
| | - Dan Truc Nguyen
- Université Libre de Bruxelles (U.L.B.), Institut de Recherches en Biologie Humaine et Moléculaire (IRIBHM), and ULB Neuroscience Institute (UNI), 1070 Brussels, Belgium
| | - Adèle Herpoel
- Université Libre de Bruxelles (U.L.B.), Institut de Recherches en Biologie Humaine et Moléculaire (IRIBHM), and ULB Neuroscience Institute (UNI), 1070 Brussels, Belgium
| | - Angéline Bilheu
- Université Libre de Bruxelles (U.L.B.), Institut de Recherches en Biologie Humaine et Moléculaire (IRIBHM), and ULB Neuroscience Institute (UNI), 1070 Brussels, Belgium
| | - Sofie Beckers
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium,Department of Neurosciences, Leuven Brain Institute, KU Leuven, 3000 Leuven, Belgium
| | - Catherine Ledent
- Université Libre de Bruxelles (U.L.B.), Institut de Recherches en Biologie Humaine et Moléculaire (IRIBHM), and ULB Neuroscience Institute (UNI), 1070 Brussels, Belgium
| | - Pierre Vanderhaeghen
- VIB-KU Leuven Center for Brain & Disease Research, 3000 Leuven, Belgium,Department of Neurosciences, Leuven Brain Institute, KU Leuven, 3000 Leuven, Belgium,Université Libre de Bruxelles (U.L.B.), Institut de Recherches en Biologie Humaine et Moléculaire (IRIBHM), and ULB Neuroscience Institute (UNI), 1070 Brussels, Belgium,Corresponding author
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Junker AD, Woodhams LG, Soh AWJ, O’Toole ET, Bayly PV, Pearson CG. Basal bodies bend in response to ciliary forces. Mol Biol Cell 2022; 33:ar146. [PMID: 36287828 PMCID: PMC9727800 DOI: 10.1091/mbc.e22-10-0468-t] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Motile cilia beat with an asymmetric waveform consisting of a power stroke that generates a propulsive force and a recovery stroke that returns the cilium back to the start. Cilia are anchored to the cell cortex by basal bodies (BBs) that are directly coupled to the ciliary doublet microtubules (MTs). We find that, consistent with ciliary forces imposing on BBs, bending patterns in BB triplet MTs are responsive to ciliary beating. BB bending varies as environmental conditions change the ciliary waveform. Bending occurs where striated fibers (SFs) attach to BBs and mutants with short SFs that fail to connect to adjacent BBs exhibit abnormal BB bending, supporting a model in which SFs couple ciliary forces between BBs. Finally, loss of the BB stability protein Poc1, which helps interconnect BB triplet MTs, prevents the normal distributed BB and ciliary bending patterns. Collectively, BBs experience ciliary forces and manage mechanical coupling of these forces to their surrounding cellular architecture for normal ciliary beating.
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Affiliation(s)
- Anthony D. Junker
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Louis G. Woodhams
- Department of Mechanical Engineering and Material Science, Washington University in St. Louis, St. Louis, MO 63130
| | - Adam W. J. Soh
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Eileen T. O’Toole
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80302
| | - Philip V. Bayly
- Department of Mechanical Engineering and Material Science, Washington University in St. Louis, St. Louis, MO 63130
| | - Chad G. Pearson
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045,*Address correspondence to: Chad G. Pearson ()
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Faubel RJ, Santos Canellas VS, Gaesser J, Beluk NH, Feinstein TN, Wang Y, Yankova M, Karunakaran KB, King SM, Ganapathiraju MK, Lo CW. Flow blockage disrupts cilia-driven fluid transport in the epileptic brain. Acta Neuropathol 2022; 144:691-706. [PMID: 35980457 DOI: 10.1007/s00401-022-02463-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 01/28/2023]
Abstract
A carpet of ependymal motile cilia lines the brain ventricular system, forming a network of flow channels and barriers that pattern cerebrospinal fluid (CSF) flow at the surface. This CSF transport system is evolutionary conserved, but its physiological function remains unknown. Here we investigated its potential role in epilepsy with studies focused on CDKL5 deficiency disorder (CDD), a neurodevelopmental disorder with early-onset epilepsy refractory to seizure medications and the most common cause of infant epilepsy. CDKL5 is a highly conserved X-linked gene suggesting its function in regulating cilia length and motion in the green alga Chlamydomonas might have implication in the etiology of CDD. Examination of the structure and function of airway motile cilia revealed both the CDD patients and the Cdkl5 knockout mice exhibit cilia lengthening and abnormal cilia motion. Similar defects were observed for brain ventricular cilia in the Cdkl5 knockout mice. Mapping ependymal cilia generated flow in the ventral third ventricle (v3V), a brain region with important physiological functions showed altered patterning of flow. Tracing of cilia-mediated inflow into v3V with fluorescent dye revealed the appearance of a flow barrier at the inlet of v3V in Cdkl5 knockout mice. Analysis of mice with a mutation in another epilepsy-associated kinase, Yes1, showed the same disturbance of cilia motion and flow patterning. The flow barrier was also observed in the Foxj1± and FOXJ1CreERT:Cdkl5y/fl mice, confirming the contribution of ventricular cilia to the flow disturbances. Importantly, mice exhibiting altered cilia-driven flow also showed increased susceptibility to anesthesia-induced seizure-like activity. The cilia-driven flow disturbance arises from altered cilia beating orientation with the disrupted polarity of the cilia anchoring rootlet meshwork. Together these findings indicate motile cilia disturbances have an essential role in CDD-associated seizures and beyond, suggesting cilia regulating kinases may be a therapeutic target for medication-resistant epilepsy.
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Affiliation(s)
- Regina J Faubel
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Veronica S Santos Canellas
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Jenna Gaesser
- Division of Child Neurology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Nancy H Beluk
- Division of Radiology, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Tim N Feinstein
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Yong Wang
- Laboratory for Fluid Physics, Pattern Formation and Biocomplexity, Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077, Göttingen, Germany
| | - Maya Yankova
- Department of Molecular Biology and Biophysics, And Electron Microscopy Facility, University of Connecticut Health Center, Farmington, CT, 06030-3305, USA
| | - Kalyani B Karunakaran
- Supercomputer Education and Research Centre, Indian Institute of Science, Bangalore, 560012, India
| | - Stephen M King
- Department of Molecular Biology and Biophysics, And Electron Microscopy Facility, University of Connecticut Health Center, Farmington, CT, 06030-3305, USA
| | - Madhavi K Ganapathiraju
- Department of Biomedical Informatics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Cecilia W Lo
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA.
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Abstract
The centrosome, consisting of centrioles and the associated pericentriolar material, is the main microtubule-organizing centre (MTOC) in animal cells. During most of interphase, the two centrosomes of a cell are joined together by centrosome cohesion into one MTOC. The most dominant element of centrosome cohesion is the centrosome linker, an interdigitating, fibrous network formed by the protein C-Nap1 anchoring a number of coiled-coil proteins including rootletin to the proximal end of centrioles. Alternatively, centrosomes can be kept together by the action of the minus end directed kinesin motor protein KIFC3 that works on interdigitating microtubules organized by both centrosomes and probably by the actin network. Although cells connect the two interphase centrosomes by several mechanisms into one MTOC, the general importance of centrosome cohesion, particularly for an organism, is still largely unclear. In this article, we review the functions of the centrosome linker and discuss how centrosome cohesion defects can lead to diseases.
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Affiliation(s)
- Hairuo Dang
- Zentrum für Molekulare Biologie der Universität Heidelberg, Deutsches Krebsforschungszentrum-ZMBH Allianz, and,Heidelberg Biosciences International Graduate School (HBIGS), Universität Heidelberg, Heidelberg 69120, Germany
| | - Elmar Schiebel
- Zentrum für Molekulare Biologie der Universität Heidelberg, Deutsches Krebsforschungszentrum-ZMBH Allianz, and
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11
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Hoffmann F, Bolz S, Junger K, Klose F, Schubert T, Woerz F, Boldt K, Ueffing M, Beyer T. TTC30A and TTC30B Redundancy Protects IFT Complex B Integrity and Its Pivotal Role in Ciliogenesis. Genes (Basel) 2022; 13:genes13071191. [PMID: 35885974 PMCID: PMC9319246 DOI: 10.3390/genes13071191] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/07/2022] [Accepted: 06/29/2022] [Indexed: 12/02/2022] Open
Abstract
Intraflagellar transport (IFT) is a microtubule-based system that supports the assembly and maintenance of cilia. The dysfunction of IFT leads to ciliopathies of variable severity. Two of the IFT-B components are the paralogue proteins TTC30A and TTC30B. To investigate whether these proteins constitute redundant functions, CRISPR/Cas9 was used to generate single TTC30A or B and double-knockout hTERT-RPE1 cells. Ciliogenesis assays showed the redundancy of both proteins while the polyglutamylation of cilia was affected in single knockouts. The localization of other IFT components was not affected by the depletion of a single paralogue. A loss of both proteins led to a severe ciliogenesis defect, resulting in no cilia formation, which was rescued by TTC30A or B. The redundancy can be explained by the highly similar interaction patterns of the paralogues; both equally interact with the IFT-B machinery. Our study demonstrates that a loss of one TTC30 paralogue can mostly be compensated by the other, thus preventing severe ciliary defects. However, cells assemble shorter cilia, which are potentially limited in their function, especially because of impaired polyglutamylation. A complete loss of both proteins leads to a deficit in IFT complex B integrity followed by disrupted IFT and subsequently no cilia formation.
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Affiliation(s)
- Felix Hoffmann
- Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany; (F.H.); (S.B.); (K.J.); (F.K.); (T.S.); (F.W.); (K.B.); (M.U.)
| | - Sylvia Bolz
- Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany; (F.H.); (S.B.); (K.J.); (F.K.); (T.S.); (F.W.); (K.B.); (M.U.)
| | - Katrin Junger
- Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany; (F.H.); (S.B.); (K.J.); (F.K.); (T.S.); (F.W.); (K.B.); (M.U.)
| | - Franziska Klose
- Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany; (F.H.); (S.B.); (K.J.); (F.K.); (T.S.); (F.W.); (K.B.); (M.U.)
| | - Timm Schubert
- Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany; (F.H.); (S.B.); (K.J.); (F.K.); (T.S.); (F.W.); (K.B.); (M.U.)
- Werner Reichardt Centre for Integrative Neuroscience (CIN), University of Tübingen, Otfried-Müller-Str. 25, 72076 Tübingen, Germany
| | - Franziska Woerz
- Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany; (F.H.); (S.B.); (K.J.); (F.K.); (T.S.); (F.W.); (K.B.); (M.U.)
| | - Karsten Boldt
- Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany; (F.H.); (S.B.); (K.J.); (F.K.); (T.S.); (F.W.); (K.B.); (M.U.)
| | - Marius Ueffing
- Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany; (F.H.); (S.B.); (K.J.); (F.K.); (T.S.); (F.W.); (K.B.); (M.U.)
| | - Tina Beyer
- Institute for Ophthalmic Research, Eberhard Karls University Tübingen, Elfriede-Aulhorn-Str. 7, 72076 Tübingen, Germany; (F.H.); (S.B.); (K.J.); (F.K.); (T.S.); (F.W.); (K.B.); (M.U.)
- Correspondence:
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12
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Yasunaga T, Wiegel J, Bergen MD, Helmstädter M, Epting D, Paolini A, Çiçek Ö, Radziwill G, Engel C, Brox T, Ronneberger O, Walentek P, Ulbrich MH, Walz G. Microridge-like structures anchor motile cilia. Nat Commun 2022; 13:2056. [PMID: 35440631 PMCID: PMC9018822 DOI: 10.1038/s41467-022-29741-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 03/30/2022] [Indexed: 01/11/2023] Open
Abstract
Several tissues contain cells with multiple motile cilia that generate a fluid or particle flow to support development and organ functions; defective motility causes human disease. Developmental cues orient motile cilia, but how cilia are locked into their final position to maintain a directional flow is not understood. Here we find that the actin cytoskeleton is highly dynamic during early development of multiciliated cells (MCCs). While apical actin bundles become increasingly more static, subapical actin filaments are nucleated from the distal tip of ciliary rootlets. Anchorage of these subapical actin filaments requires the presence of microridge-like structures formed during MCC development, and the activity of Nonmuscle Myosin II. Optogenetic manipulation of Ezrin, a core component of the microridge actin-anchoring complex, or inhibition of Myosin Light Chain Kinase interfere with rootlet anchorage and orientation. These observations identify microridge-like structures as an essential component of basal body rootlet anchoring in MCCs.
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Affiliation(s)
- Takayuki Yasunaga
- Department of Medicine IV, University Freiburg Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany
| | - Johannes Wiegel
- Department of Medicine IV, University Freiburg Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany
| | - Max D Bergen
- Department of Medicine IV, University Freiburg Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany
| | - Martin Helmstädter
- Department of Medicine IV, University Freiburg Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany
| | - Daniel Epting
- Department of Medicine IV, University Freiburg Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany
| | - Andrea Paolini
- Department of Medicine IV, University Freiburg Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Schaenzlestrasse 1, 79104, Freiburg, Germany
| | - Özgün Çiçek
- Pattern Recognition and Image Processing, Department of Computer Science, University of Freiburg, Georges-Köhler-Allee 52, 79110, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany
| | - Gerald Radziwill
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany
| | - Christina Engel
- Department of Medicine IV, University Freiburg Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany
| | - Thomas Brox
- Pattern Recognition and Image Processing, Department of Computer Science, University of Freiburg, Georges-Köhler-Allee 52, 79110, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany
| | - Olaf Ronneberger
- Pattern Recognition and Image Processing, Department of Computer Science, University of Freiburg, Georges-Köhler-Allee 52, 79110, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany
| | - Peter Walentek
- Department of Medicine IV, University Freiburg Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany
| | - Maximilian H Ulbrich
- Department of Medicine IV, University Freiburg Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany
| | - Gerd Walz
- Department of Medicine IV, University Freiburg Medical Center, Faculty of Medicine, University of Freiburg, Hugstetter Strasse 55, 79106, Freiburg, Germany.
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany.
- CIBSS Centre for Integrative Biological Signalling Studies, University of Freiburg, Schänzlestrasse 18, 79104, Freiburg, Germany.
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13
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Planar polarity in primate cone photoreceptors: a potential role in Stiles Crawford effect phototropism. Commun Biol 2022; 5:89. [PMID: 35075261 PMCID: PMC8786850 DOI: 10.1038/s42003-021-02998-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Accepted: 12/15/2021] [Indexed: 11/18/2022] Open
Abstract
Human cone phototropism is a key mechanism underlying the Stiles-Crawford effect, a psychophysiological phenomenon according to which photoreceptor outer/inner segments are aligned along with the direction of incoming light. However, such photomechanical movements of photoreceptors remain elusive in mammals. We first show here that primate cone photoreceptors have a planar polarity organized radially around the optical center of the eye. This planar polarity, based on the structure of the cilium and calyceal processes, is highly reminiscent of the planar polarity of the hair cells and their kinocilium and stereocilia. Secondly, we observe under super-high resolution expansion microscopy the cytoskeleton and Usher proteins architecture in the photoreceptors, which appears to establish a mechanical continuity between the outer and inner segments. Taken together, these results suggest a comprehensive cellular mechanism consistent with an active phototropism of cones toward the optical center of the eye, and thus with the Stiles-Crawford effect. Verschueren et al. expand our understanding of the Stiles-Crawford effect in mammals by using super-high resolution expansion microscopy of the adult macaque eye. They show that cone photoreceptors have a planar polarity organized radially around the optical center of the eye and that Usher proteins establish a mechanical continuity between the outer and inner segments, which sheds light on the Stiles-Crawford effect in this species.
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14
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Nommick A, Boutin C, Rosnet O, Schirmer C, Bazellières E, Thomé V, Loiseau E, Viallat A, Kodjabachian L. Lrrcc1 and Ccdc61 are conserved effectors of multiciliated cell function. J Cell Sci 2022; 135:274401. [DOI: 10.1242/jcs.258960] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 01/05/2022] [Indexed: 11/20/2022] Open
Abstract
Ciliated epithelia perform essential functions across animal evolution, ranging from locomotion of marine organisms to mucociliary clearance of airways in mammals. These epithelia are composed of multiciliated cells (MCCs) harbouring myriads of motile cilia, which rest on modified centrioles called basal bodies (BBs), and beat coordinately to generate directed fluid flows. Thus, BB biogenesis and organization is central to MCC function. In basal eukaryotes, the coiled-coil domain proteins Lrrcc1 and Ccdc61 were shown to be required for proper BB construction and function. Here, we used the Xenopus embryonic ciliated epidermis to characterize Lrrcc1 and Ccdc61 in vertebrate MCCs. We found that they both encode BB components, localized proximally at the junction with striated rootlets. Knocking down either gene caused defects in BB docking, spacing, and polarization. Moreover, their depletion impaired the apical cytoskeleton, and altered ciliary beating. Consequently, cilia-powered fluid flow was greatly reduced in morphant tadpoles, which displayed enhanced mortality when exposed to pathogenic bacteria. This work illustrates how integration across organizational scales make elementary BB components essential for the emergence of the physiological function of ciliated epithelia.
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Affiliation(s)
- Aude Nommick
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Camille Boutin
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Olivier Rosnet
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Claire Schirmer
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Elsa Bazellières
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Virginie Thomé
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
| | - Etienne Loiseau
- Aix Marseille Univ, CNRS, CINaM, Turing Center for Living Systems, Marseille, France
| | - Annie Viallat
- Aix Marseille Univ, CNRS, CINaM, Turing Center for Living Systems, Marseille, France
| | - Laurent Kodjabachian
- Aix Marseille Univ, CNRS, IBDM, Turing Center for Living Systems, Marseille, France
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15
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Sato Y, Mustafina KR, Luo Y, Martini C, Thomas DY, Wiseman PW, Hanrahan JW. Nonspecific binding of common anti-CFTR antibodies in ciliated cells of human airway epithelium. Sci Rep 2021; 11:23256. [PMID: 34853321 PMCID: PMC8636639 DOI: 10.1038/s41598-021-02420-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 11/11/2021] [Indexed: 11/10/2022] Open
Abstract
There is evidence that the cystic fibrosis transmembrane conductance regulator (CFTR) anion channel is highly expressed at the apical pole of ciliated cells in human bronchial epithelium (HBE), however recent studies have detected little CFTR mRNA in those cells. To understand this discrepancy we immunostained well differentiated primary HBE cells using CFTR antibodies. We confirmed apical immunofluorescence in ciliated cells and quantified the covariance of the fluorescence signals and that of an antibody against the ciliary marker centrin-2 using image cross-correlation spectroscopy (ICCS). Super-resolution stimulated emission depletion (STED) imaging localized the immunofluorescence in distinct clusters at the bases of the cilia. However, similar apical fluorescence was observed when the monoclonal CFTR antibodies 596, 528 and 769 were used to immunostain ciliated cells expressing F508del-CFTR, or cells lacking CFTR due to a Class I mutation. A BLAST search using the CFTR epitope identified a similar amino acid sequence in the ciliary protein rootletin X1. Its expression level correlated with the intensity of immunostaining by CFTR antibodies and it was detected by 596 antibody after transfection into CFBE cells. These results may explain the high apparent expression of CFTR in ciliated cells and reports of anomalous apical immunofluorescence in well differentiated cells that express F508del-CFTR.
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Affiliation(s)
- Yukiko Sato
- Department of Physiology, McGill University, McIntyre Medical Sciences Building, 3655 Promenade Sir William Osler, Montréal, QC, H3G 1Y6, Canada.,Cystic Fibrosis Translational Research Centre, McGill University, Montréal, Canada
| | - Kamila R Mustafina
- Cystic Fibrosis Translational Research Centre, McGill University, Montréal, Canada.,Department of Chemistry, McGill University, Montréal, Canada
| | - Yishan Luo
- Department of Physiology, McGill University, McIntyre Medical Sciences Building, 3655 Promenade Sir William Osler, Montréal, QC, H3G 1Y6, Canada.,Cystic Fibrosis Translational Research Centre, McGill University, Montréal, Canada
| | - Carolina Martini
- Department of Physiology, McGill University, McIntyre Medical Sciences Building, 3655 Promenade Sir William Osler, Montréal, QC, H3G 1Y6, Canada.,Cystic Fibrosis Translational Research Centre, McGill University, Montréal, Canada
| | - David Y Thomas
- Cystic Fibrosis Translational Research Centre, McGill University, Montréal, Canada.,Department of Biochemistry, McGill University, Montréal, Canada
| | - Paul W Wiseman
- Cystic Fibrosis Translational Research Centre, McGill University, Montréal, Canada.,Department of Chemistry, McGill University, Montréal, Canada.,Department of Physics, McGill University, Montréal, Canada
| | - John W Hanrahan
- Department of Physiology, McGill University, McIntyre Medical Sciences Building, 3655 Promenade Sir William Osler, Montréal, QC, H3G 1Y6, Canada. .,Cystic Fibrosis Translational Research Centre, McGill University, Montréal, Canada. .,Research Institute - McGill University Health Centre, Montréal, Canada.
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16
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Valentine M, Van Houten J. Using Paramecium as a Model for Ciliopathies. Genes (Basel) 2021; 12:genes12101493. [PMID: 34680887 PMCID: PMC8535419 DOI: 10.3390/genes12101493] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 09/14/2021] [Accepted: 09/17/2021] [Indexed: 01/26/2023] Open
Abstract
Paramecium has served as a model organism for the studies of many aspects of genetics and cell biology: non-Mendelian inheritance, genome duplication, genome rearrangements, and exocytosis, to name a few. However, the large number and patterning of cilia that cover its surface have inspired extraordinary ultrastructural work. Its swimming patterns inspired exquisite electrophysiological studies that led to a description of the bioelectric control of ciliary motion. A genetic dissection of swimming behavior moved the field toward the genes and gene products underlying ciliary function. With the advent of molecular technologies, it became clear that there was not only great conservation of ciliary structure but also of the genes coding for ciliary structure and function. It is this conservation and the legacy of past research that allow us to use Paramecium as a model for cilia and ciliary diseases called ciliopathies. However, there would be no compelling reason to study Paramecium as this model if there were no new insights into cilia and ciliopathies to be gained. In this review, we present studies that we believe will do this. For example, while the literature continues to state that immotile cilia are sensory and motile cilia are not, we will provide evidence that Paramecium cilia are clearly sensory. Other examples show that while a Paramecium protein is highly conserved it takes a different interacting partner or conducts a different ion than expected. Perhaps these exceptions will provoke new ideas about mammalian systems.
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Affiliation(s)
- Megan Valentine
- State University of New York at Plattsburgh, 101 Broad Street, Plattsburgh, NY 12901, USA;
| | - Judith Van Houten
- Department of Biology, University of Vermont, 120 Marsh Life Science, 109 Carrigan Drive, Burlington, VT 05405, USA
- Correspondence:
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17
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The 3D organisation of mitochondria in primate photoreceptors. Sci Rep 2021; 11:18863. [PMID: 34552195 PMCID: PMC8458444 DOI: 10.1038/s41598-021-98409-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Accepted: 08/17/2021] [Indexed: 11/08/2022] Open
Abstract
Vertebrate photoreceptors contain large numbers of closely-packed mitochondria which sustain the high metabolic demands of these cells. These mitochondria populations are dynamic and undergo fusion and fission events. This activity serves to maintain the population in a healthy state. In the event of mitochondrial damage, sub-domains, or indeed whole mitochondria, can be degraded and population homeostasis achieved. If this process is overwhelmed cell death may result. Death of photoreceptors contributes to loss of vision in aging individuals and is associated with many eye diseases. In this study we used serial block face scanning electron microscopy of adult Macaca fascicularis retinae to examine the 3D structure of mitochondria in rod and cone photoreceptors. We show that healthy-looking photoreceptors contain mitochondria exhibiting a range of shapes which are associated with different regions of the cell. In some photoreceptors we observe mitochondrial swelling and other changes often associated with cellular stress. In rods and cones that appear stressed we identify elongated domains of mitochondria with densely-packed normal cristae associated with photoreceptor ciliary rootlet bundles. We observe mitochondrial fission and mitochondrion fragments localised to these domains. Swollen mitochondria with few intact cristae are located towards the periphery of the photoreceptor inner-segment in rods, whilst they are found throughout the cell in cones. Swollen mitochondria exhibit sites on the mitochondrial inner membrane which have undergone complex invagination resulting in membranous, electron-dense aggregates. Membrane contact occurs between the mitochondrion and the photoreceptor plasma membrane in the vicinity of these aggregates, and a series of subsequent membrane fusions results in expulsion of the mitochondrial aggregate from the photoreceptor. These events are primarily associated with rods. The potential fate of this purged material and consequences of its clearance by retinal pigment epithelia are discussed.
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18
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Wensel TG, Potter VL, Moye A, Zhang Z, Robichaux MA. Structure and dynamics of photoreceptor sensory cilia. Pflugers Arch 2021; 473:1517-1537. [PMID: 34050409 PMCID: PMC11216635 DOI: 10.1007/s00424-021-02564-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 04/07/2021] [Accepted: 04/08/2021] [Indexed: 02/06/2023]
Abstract
The rod and cone photoreceptor cells of the vertebrate retina have highly specialized structures that enable them to carry out their function of light detection over a broad range of illumination intensities with optimized spatial and temporal resolution. Most prominent are their unusually large sensory cilia, consisting of outer segments packed with photosensitive disc membranes, a connecting cilium with many features reminiscent of the primary cilium transition zone, and a pair of centrioles forming a basal body which serves as the platform upon which the ciliary axoneme is assembled. These structures form a highway through which an enormous flux of material moves on a daily basis to sustain the continual turnover of outer segment discs and the energetic demands of phototransduction. After decades of study, the details of the fine structure and distribution of molecular components of these structures are still incompletely understood, but recent advances in cellular imaging techniques and animal models of inherited ciliary defects are yielding important new insights. This knowledge informs our understanding both of the mechanisms of trafficking and assembly and of the pathophysiological mechanisms of human blinding ciliopathies.
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Affiliation(s)
- Theodore G Wensel
- Vera and Marrs McLean Department of Biochemistry and Molecular Biology and Developmental Biology Graduate Program, Baylor College of Medicine, Houston, TX, 77030, USA.
| | - Valencia L Potter
- Vera and Marrs McLean Department of Biochemistry and Molecular Biology and Developmental Biology Graduate Program, Baylor College of Medicine, Houston, TX, 77030, USA
- Medical Scientist Training Program (MSTP), Baylor College of Medicine, Houston, TX, 77030, USA
| | - Abigail Moye
- Vera and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Zhixian Zhang
- Vera and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Michael A Robichaux
- Departments of Ophthalmology and Biochemistry, West Virginia University, Morgantown, WV, USA
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19
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Abstract
To gain a holistic understanding of cellular function, we must understand not just the role of individual organelles, but also how multiple macromolecular assemblies function collectively. Centrioles produce fundamental cellular processes through their ability to organise cytoskeletal fibres. In addition to nucleating microtubules, centrioles form lesser-known polymers, termed rootlets. Rootlets were identified over a 100 years ago and have been documented morphologically since by electron microscopy in different eukaryotic organisms. Rootlet-knockout animals have been created in various systems, providing insight into their physiological functions. However, the precise structure and function of rootlets is still enigmatic. Here, I consider common themes of rootlet function and assembly across diverse cellular systems. I suggest that the capability of rootlets to form physical links from centrioles to other cellular structures is a general principle unifying their functions in diverse cells and serves as an example of how cellular function arises from collective organellar activity.
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Affiliation(s)
- Robert Mahen
- The Medical Research Council Cancer Unit, University of Cambridge, Hills Road, Cambridge CB2 0XZ, UK
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20
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Doucette LP, Noel NCL, Zhai Y, Xu M, Caluseriu O, Hoang SC, Radziwon AJ, MacDonald IM. Whole exome sequencing reveals putatively novel associations in retinopathies and drusen formation. Eur J Hum Genet 2021; 29:1171-1185. [PMID: 33776059 PMCID: PMC8385108 DOI: 10.1038/s41431-021-00872-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 01/24/2021] [Accepted: 03/12/2021] [Indexed: 02/02/2023] Open
Abstract
Inherited retinal dystrophies (IRDs) affect 1 in 3000 individuals worldwide and are genetically heterogeneous, with over 270 identified genes and loci; however, there are still many identified disorders with no current genetic etiology. Whole exome sequencing (WES) provides a hypothesis-free first examination of IRD patients in either a clinical or research setting to identify the genetic cause of disease. We present a study of IRD in ten families from Alberta, Canada, through the lens of novel gene discovery. We identify the genetic etiology of IRDs in three of the families to be variants in known disease-associated genes, previously missed by clinical investigations. In addition, we identify two potentially novel associations: LRP1 in early-onset drusen formation and UBE2U in a multi-system condition presenting with retinoschisis, cataracts, learning disabilities, and developmental delay. We also describe interesting results in our unsolved cases to provide further information to other investigators of these blinding conditions.
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Affiliation(s)
- Lance P Doucette
- Department of Ophthalmology & Visual Sciences, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Nicole C L Noel
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Yi Zhai
- Department of Ophthalmology & Visual Sciences, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Manlong Xu
- Department of Ophthalmology & Visual Sciences, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Oana Caluseriu
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Stephanie C Hoang
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Alina J Radziwon
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada
| | - Ian M MacDonald
- Department of Ophthalmology & Visual Sciences, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada.
- Department of Medical Genetics, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB, Canada.
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21
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Gilbert MC, Tetrault E, Packard M, Navon D, Albertson RC. Ciliary Rootlet Coiled-Coil 2 (crocc2) Is Associated with Evolutionary Divergence and Plasticity of Cichlid Jaw Shape. Mol Biol Evol 2021; 38:3078-3092. [PMID: 33720362 PMCID: PMC8321518 DOI: 10.1093/molbev/msab071] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Cichlid fishes exhibit rapid, extensive, and replicative adaptive radiation in feeding morphology. Plasticity of the cichlid jaw has also been well documented, and this combination of iterative evolution and developmental plasticity has led to the proposition that the cichlid feeding apparatus represents a morphological "flexible stem." Under this scenario, the fixation of environmentally sensitive genetic variation drives evolutionary divergence along a phenotypic axis established by the initial plastic response. Thus, if plasticity is predictable then so too should be the evolutionary response. We set out to explore these ideas at the molecular level by identifying genes that underlie both the evolution and plasticity of the cichlid jaw. As a first step, we fine-mapped an environment-specific quantitative trait loci for lower jaw shape in cichlids, and identified a nonsynonymous mutation in the ciliary rootlet coiled-coil 2 (crocc2), which encodes a major structural component of the primary cilium. Given that primary cilia play key roles in skeletal mechanosensing, we reasoned that this gene may confer its effects by regulating the sensitivity of bone to respond to mechanical input. Using both cichlids and zebrafish, we confirmed this prediction through a series of experiments targeting multiple levels of biological organization. Taken together, our results implicate crocc2 as a novel mediator of bone formation, plasticity, and evolution.
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Affiliation(s)
- Michelle C Gilbert
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA, USA
| | - Emily Tetrault
- Graduate Program in Molecular and Cellular Biology, University of Massachusetts, Amherst, MA, USA
| | - Mary Packard
- Department of Biology, University of Massachusetts, Amherst, MA, USA
| | - Dina Navon
- Graduate Program in Organismic and Evolutionary Biology, University of Massachusetts, Amherst, MA, USA
| | - R Craig Albertson
- Department of Biology, University of Massachusetts, Amherst, MA, USA
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22
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Sánchez-Bellver L, Toulis V, Marfany G. On the Wrong Track: Alterations of Ciliary Transport in Inherited Retinal Dystrophies. Front Cell Dev Biol 2021; 9:623734. [PMID: 33748110 PMCID: PMC7973215 DOI: 10.3389/fcell.2021.623734] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/09/2021] [Indexed: 01/14/2023] Open
Abstract
Ciliopathies are a group of heterogeneous inherited disorders associated with dysfunction of the cilium, a ubiquitous microtubule-based organelle involved in a broad range of cellular functions. Most ciliopathies are syndromic, since several organs whose cells produce a cilium, such as the retina, cochlea or kidney, are affected by mutations in ciliary-related genes. In the retina, photoreceptor cells present a highly specialized neurosensory cilium, the outer segment, stacked with membranous disks where photoreception and phototransduction occurs. The daily renewal of the more distal disks is a unique characteristic of photoreceptor outer segments, resulting in an elevated protein demand. All components necessary for outer segment formation, maintenance and function have to be transported from the photoreceptor inner segment, where synthesis occurs, to the cilium. Therefore, efficient transport of selected proteins is critical for photoreceptor ciliogenesis and function, and any alteration in either cargo delivery to the cilium or intraciliary trafficking compromises photoreceptor survival and leads to retinal degeneration. To date, mutations in more than 100 ciliary genes have been associated with retinal dystrophies, accounting for almost 25% of these inherited rare diseases. Interestingly, not all mutations in ciliary genes that cause retinal degeneration are also involved in pleiotropic pathologies in other ciliated organs. Depending on the mutation, the same gene can cause syndromic or non-syndromic retinopathies, thus emphasizing the highly refined specialization of the photoreceptor neurosensory cilia, and raising the possibility of photoreceptor-specific molecular mechanisms underlying common ciliary functions such as ciliary transport. In this review, we will focus on ciliary transport in photoreceptor cells and discuss the molecular complexity underpinning retinal ciliopathies, with a special emphasis on ciliary genes that, when mutated, cause either syndromic or non-syndromic retinal ciliopathies.
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Affiliation(s)
- Laura Sánchez-Bellver
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
| | - Vasileios Toulis
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- CIBERER, ISCIII, Universitat de Barcelona, Barcelona, Spain
| | - Gemma Marfany
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
- CIBERER, ISCIII, Universitat de Barcelona, Barcelona, Spain
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23
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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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Striebel JF, Race B, Leung JM, Schwartz C, Chesebro B. Prion-induced photoreceptor degeneration begins with misfolded prion protein accumulation in cones at two distinct sites: cilia and ribbon synapses. Acta Neuropathol Commun 2021; 9:17. [PMID: 33509294 PMCID: PMC7845122 DOI: 10.1186/s40478-021-01120-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 01/09/2021] [Indexed: 12/15/2022] Open
Abstract
Accumulation of misfolded host proteins is central to neuropathogenesis of numerous human brain diseases including prion and prion-like diseases. Neurons of retina are also affected by these diseases. Previously, our group and others found that prion-induced retinal damage to photoreceptor cells in mice and humans resembled pathology of human retinitis pigmentosa caused by mutations in retinal proteins. Here, using confocal, epifluorescent and electron microscopy we followed deposition of disease-associated prion protein (PrPSc) and its association with damage to critical retinal structures following intracerebral prion inoculation. The earliest time and place of retinal PrPSc deposition was 67 days post-inoculation (dpi) on the inner segment (IS) of cone photoreceptors. At 104 and 118 dpi, PrPSc was associated with the base of cilia and swollen cone inner segments, suggesting ciliopathy as a pathogenic mechanism. By 118 dpi, PrPSc was deposited in both rods and cones which showed rootlet damage in the IS, and photoreceptor cell death was indicated by thinning of the outer nuclear layer. In the outer plexiform layer (OPL) in uninfected mice, normal host PrP (PrPC) was mainly associated with cone bipolar cell processes, but in infected mice, at 118 dpi, PrPSc was detected on cone and rod bipolar cell dendrites extending into ribbon synapses. Loss of ribbon synapses in cone pedicles and rod spherules in the OPL was observed to precede destruction of most rods and cones over the next 2–3 weeks. However, bipolar cells and horizontal cells were less damaged, indicating high selectivity among neurons for injury by prions. PrPSc deposition in cone and rod inner segments and on the bipolar cell processes participating in ribbon synapses appear to be critical early events leading to damage and death of photoreceptors after prion infection. These mechanisms may also occur in human retinitis pigmentosa and prion-like diseases, such as AD.
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25
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Persico V, Callaini G, Riparbelli MG. Sas-4 Colocalizes with the Ciliary Rootlets of the Drosophila Sensory Organs. J Dev Biol 2021; 9:jdb9010001. [PMID: 33466292 PMCID: PMC7839044 DOI: 10.3390/jdb9010001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 12/18/2020] [Accepted: 12/29/2020] [Indexed: 11/24/2022] Open
Abstract
The Drosophila eye displays peculiar sensory organs of unknown function, the mechanosensory bristles, that are intercalated among the adjacent ommatidia. Like the other Drosophila sensory organs, the mechanosensory bristles consist of a bipolar neuron and two tandemly aligned centrioles, the distal of which nucleates the ciliary axoneme and represents the starting point of the ciliary rootlets. We report here that the centriole associated protein Sas-4 colocalizes with the short ciliary rootlets of the mechanosensory bristles and with the elongated rootlets of chordotonal and olfactory neurons. This finding suggests an unexpected cytoplasmic localization of Sas-4 protein and points to a new underscored role for this protein. Moreover, we observed that the sheath cells associated with the sensory neurons also display two tandemly aligned centrioles but lacks ciliary axonemes, suggesting that the dendrites of the sensory neurons are dispensable for the assembly of aligned centrioles and rootlets.
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Affiliation(s)
- Veronica Persico
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy; (V.P.); (M.G.R.)
| | - Giuliano Callaini
- Department of Medical Biotechnologies, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy
- Correspondence:
| | - Maria Giovanna Riparbelli
- Department of Life Sciences, University of Siena, Via Aldo Moro 2, 53100 Siena, Italy; (V.P.); (M.G.R.)
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26
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Chen HY, Kelley RA, Li T, Swaroop A. Primary cilia biogenesis and associated retinal ciliopathies. Semin Cell Dev Biol 2020; 110:70-88. [PMID: 32747192 PMCID: PMC7855621 DOI: 10.1016/j.semcdb.2020.07.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/14/2020] [Accepted: 07/18/2020] [Indexed: 12/19/2022]
Abstract
The primary cilium is a ubiquitous microtubule-based organelle that senses external environment and modulates diverse signaling pathways in different cell types and tissues. The cilium originates from the mother centriole through a complex set of cellular events requiring hundreds of distinct components. Aberrant ciliogenesis or ciliary transport leads to a broad spectrum of clinical entities with overlapping yet highly variable phenotypes, collectively called ciliopathies, which include sensory defects and syndromic disorders with multi-organ pathologies. For efficient light detection, photoreceptors in the retina elaborate a modified cilium known as the outer segment, which is packed with membranous discs enriched for components of the phototransduction machinery. Retinopathy phenotype involves dysfunction and/or degeneration of the light sensing photoreceptors and is highly penetrant in ciliopathies. This review will discuss primary cilia biogenesis and ciliopathies, with a focus on the retina, and the role of CP110-CEP290-CC2D2A network. We will also explore how recent technologies can advance our understanding of cilia biology and discuss new paradigms for developing potential therapies of retinal ciliopathies.
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Affiliation(s)
- Holly Y Chen
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA.
| | - Ryan A Kelley
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Tiansen Li
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Anand Swaroop
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA.
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27
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Gilloteaux J. Primary cilia in the Syrian hamster biliary tract: Bile flow antennae and outlooks about signaling on the hepato-biliary-pancreatic stem cells. TRANSLATIONAL RESEARCH IN ANATOMY 2020. [DOI: 10.1016/j.tria.2020.100063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
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28
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Ko D, Kim J, Rhee K, Choi HJ. Identification of a Structurally Dynamic Domain for Oligomer Formation in Rootletin. J Mol Biol 2020; 432:3915-3932. [DOI: 10.1016/j.jmb.2020.04.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 03/10/2020] [Accepted: 04/13/2020] [Indexed: 10/24/2022]
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29
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Magnadóttir B, Uysal-Onganer P, Kraev I, Svansson V, Hayes P, Lange S. Deiminated proteins and extracellular vesicles - Novel serum biomarkers in whales and orca. COMPARATIVE BIOCHEMISTRY AND PHYSIOLOGY D-GENOMICS & PROTEOMICS 2020; 34:100676. [PMID: 32114311 DOI: 10.1016/j.cbd.2020.100676] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/16/2020] [Accepted: 02/17/2020] [Indexed: 02/06/2023]
Abstract
Peptidylarginine deiminases (PADs) are a family of phylogenetically conserved calcium-dependent enzymes which cause post-translational protein deimination. This can result in neoepitope generation, affect gene regulation and allow for protein moonlighting via functional and structural changes in target proteins. Extracellular vesicles (EVs) carry cargo proteins and genetic material and are released from cells as part of cellular communication. EVs are found in most body fluids where they can be useful biomarkers for assessment of health status. Here, serum-derived EVs were profiled, and post-translationally deiminated proteins and EV-related microRNAs are described in 5 ceataceans: minke whale, fin whale, humpback whale, Cuvier's beaked whale and orca. EV-serum profiles were assessed by transmission electron microscopy and nanoparticle tracking analysis. EV profiles varied between the 5 species and were identified to contain deiminated proteins and selected key inflammatory and metabolic microRNAs. A range of proteins, critical for immune responses and metabolism were identified to be deiminated in cetacean sera, with some shared KEGG pathways of deiminated proteins relating to immunity and physiology, while some KEGG pathways were species-specific. This is the first study to characterise and profile EVs and to report deiminated proteins and putative effects of protein-protein interaction networks via such post-translationald deimination in cetaceans, revealing key immune and metabolic factors to undergo this post-translational modification. Deiminated proteins and EVs profiles may possibly be developed as new biomarkers for assessing health status of sea mammals.
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Affiliation(s)
- Bergljót Magnadóttir
- Institute for Experimental Pathology, University of Iceland, Keldur v. Vesturlandsveg, 112 Reykjavik, Iceland.
| | - Pinar Uysal-Onganer
- Cancer Research Group, School of Life Sciences, University of Westminster, London W1W 6UW, UK.
| | - Igor Kraev
- Electron Microscopy Suite, Faculty of Science, Technology, Engineering and Mathematics, Open University, Milton Keynes MK7 6AA, UK.
| | - Vilhjálmur Svansson
- Institute for Experimental Pathology, University of Iceland, Keldur v. Vesturlandsveg, 112 Reykjavik, Iceland
| | - Polly Hayes
- Tissue Architecture and Regeneration Research Group, School of Life Sciences, University of Westminster, London W1W 6UW, UK.
| | - Sigrun Lange
- Tissue Architecture and Regeneration Research Group, School of Life Sciences, University of Westminster, London W1W 6UW, UK.
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30
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Stereocilia Rootlets: Actin-Based Structures That Are Essential for Structural Stability of the Hair Bundle. Int J Mol Sci 2020; 21:ijms21010324. [PMID: 31947734 PMCID: PMC6981779 DOI: 10.3390/ijms21010324] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2019] [Revised: 12/30/2019] [Accepted: 01/01/2020] [Indexed: 12/04/2022] Open
Abstract
Sensory hair cells of the inner ear rely on the hair bundle, a cluster of actin-filled stereocilia, to transduce auditory and vestibular stimuli into electrical impulses. Because they are long and thin projections, stereocilia are most prone to damage at the point where they insert into the hair cell’s soma. Moreover, this is the site of stereocilia pivoting, the mechanical movement that induces transduction, which additionally weakens this area mechanically. To bolster this fragile area, hair cells construct a dense core called the rootlet at the base of each stereocilium, which extends down into the actin meshwork of the cuticular plate and firmly anchors the stereocilium. Rootlets are constructed with tightly packed actin filaments that extend from stereocilia actin filaments which are wrapped with TRIOBP; in addition, many other proteins contribute to the rootlet and its associated structures. Rootlets allow stereocilia to sustain innumerable deflections over their lifetimes and exemplify the unique manner in which sensory hair cells exploit actin and its associated proteins to carry out the function of mechanotransduction.
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31
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Criscitiello MF, Kraev I, Lange S. Deiminated proteins in extracellular vesicles and serum of llama (Lama glama)-Novel insights into camelid immunity. Mol Immunol 2020; 117:37-53. [PMID: 31733447 PMCID: PMC7112542 DOI: 10.1016/j.molimm.2019.10.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 10/05/2019] [Accepted: 10/23/2019] [Indexed: 02/07/2023]
Abstract
Peptidylarginine deiminases (PADs) are phylogenetically conserved calcium-dependent enzymes which post-translationally convert arginine into citrulline in target proteins in an irreversible manner, causing functional and structural changes in target proteins. Protein deimination causes generation of neo-epitopes, affects gene regulation and also allows for protein moonlighting. Furthermore, PADs have been found to be a phylogenetically conserved regulator for extracellular vesicle (EVs) release. EVs are found in most body fluids and participate in cellular communication via transfer of cargo proteins and genetic material. In this study, post-translationally deiminated proteins in serum and serum-EVs are described for the first time in camelids, using the llama (Lama glama L. 1758) as a model animal. We report a poly-dispersed population of llama serum EVs, positive for phylogenetically conserved EV-specific markers and characterised by TEM. In serum, 103 deiminated proteins were overall identified, including key immune and metabolic mediators including complement components, immunoglobulin-based nanobodies, adiponectin and heat shock proteins. In serum, 60 deiminated proteins were identified that were not in EVs, and 25 deiminated proteins were found to be unique to EVs, with 43 shared deiminated protein hits between both serum and EVs. Deiminated histone H3, a marker of neutrophil extracellular trap formation, was also detected in llama serum. PAD homologues were identified in llama serum by Western blotting, via cross reaction with human PAD antibodies, and detected at an expected 70 kDa size. This is the first report of deiminated proteins in serum and EVs of a camelid species, highlighting a hitherto unrecognized post-translational modification in key immune and metabolic proteins in camelids, which may be translatable to and inform a range of human metabolic and inflammatory pathologies.
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Affiliation(s)
- Michael F Criscitiello
- Comparative Immunogenetics Laboratory, Department of Veterinary Pathobiology, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX, 77843, USA; Department of Microbial Pathogenesis and Immunology, College of Medicine, Texas A&M Health Science Center, Texas A&M University, College Station, TX, 77843, USA.
| | - Igor Kraev
- Electron Microscopy Suite, Faculty of Science, Technology, Engineering and Mathematics, Open University, Milton Keynes, MK7 6AA, UK.
| | - Sigrun Lange
- Tissue Architecture and Regeneration Research Group, School of Life Sciences, University of Westminster, London W1W 6UW, UK.
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32
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Powell L, Samarakoon YH, Ismail S, Sayer JA. ARL3, a small GTPase with a functionally conserved role in primary cilia and immune synapses. Small GTPases 2019; 12:167-176. [PMID: 31826708 DOI: 10.1080/21541248.2019.1703466] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The primary cilium and the immunological synapse are both specialized functional plasma membrane domains that share several similarities. Signalling output of membrane domains is regulated, spatially and temporally, by segregating and focusing lipids and proteins. ARL3, a small GTPase, plays a major role in concentrating lipid-modified proteins in both the immunological synapse and the primary cilia. Here in this review we will introduce the role of ARL3 in health and disease and its role in polarizing signalling at the primary cilia and immunological synapses.
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Affiliation(s)
- Laura Powell
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Newcastle upon Tyne, UK
| | - Youhani H Samarakoon
- Spatial segregation of signalling Lab, Beatson Institute for Cancer Research, Glasgow, UK.,Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - Shehab Ismail
- Spatial segregation of signalling Lab, Beatson Institute for Cancer Research, Glasgow, UK.,Institute of Cancer Sciences, University of Glasgow, Glasgow, UK
| | - John A Sayer
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, International Centre for Life, Newcastle upon Tyne, UK.,Renal Services, The Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, UK.,NIHR Newcastle Biomedical Research Centre, Newcastle upon Tyne, UK
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33
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Nabi A, Yano J, Valentine MS, Picariello T, Van Houten JL. SF-Assemblin genes in Paramecium: phylogeny and phenotypes of RNAi silencing on the ciliary-striated rootlets and surface organization. Cilia 2019; 8:2. [PMID: 31673332 PMCID: PMC6819543 DOI: 10.1186/s13630-019-0062-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 10/10/2019] [Indexed: 11/17/2022] Open
Abstract
Background Cilia emanate from basal bodies just underneath the cell membrane. Basal bodies must withstand torque from the ciliary beat and be appropriately spaced for cilia to beat in metachronal waves. Basal body rootlets provide stability for motile cilia. Paramecium has three. Our focus is on the largest one, the striated rootlet (SR). Paramecium basal bodies align in straight rows. Previously we found a potential role for the SR in this alignment. Here we present a phylogeny of the Paramecium homologs of the SF-Assemblin gene of the SR of Chlamydomonas, and the organization of these genes. We describe the phenotypes from RNA interference (RNAi) silencing of genes and gene groups. Methods Phenotypes of the RNAi depletions were characterized by immunofluorescence (IF), electron microscopy, and mass spectrometry. Results We found 30 genes for Paramecium SF-Assemblin homologs (SFA) organized into 13 Paralog Groups (further categorized in five Structural Groups). Representatives of Paralog Groups were found in the SRs. Silencing the transcripts of any of the Structural Groups correlates with misaligned rows of basal bodies, SRs, and cortical units. The silencing of Structural Groups was key and gave us the ability to systematically disrupt SR structures and cell surface organization. Conclusions Silencing of SFA genes and Paralog Groups shows no effects on the SR or the cell surface organization. Silencing of the larger Structural Groups has an enormous impact on rows of basal bodies, SRs and cortical units, and SR striations, and length. Misaligned basal bodies have cilia causing the cells to swim in abnormal paths.
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Affiliation(s)
- Ashikun Nabi
- 1University of Vermont, Burlington, VT 05405 USA.,4Present Address: Molecular, Cellular and Developmental Biology, Yale University, New Haven, CT 06511 USA
| | - Junji Yano
- 1University of Vermont, Burlington, VT 05405 USA
| | - Megan S Valentine
- 2State University of New York at Plattsburgh, Plattsburgh, NY 12901 USA
| | - Tyler Picariello
- 3University of Massachusetts Medical School, Worcester, MA 01655 USA
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Joukov V, De Nicolo A. The Centrosome and the Primary Cilium: The Yin and Yang of a Hybrid Organelle. Cells 2019; 8:E701. [PMID: 31295970 PMCID: PMC6678760 DOI: 10.3390/cells8070701] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 07/04/2019] [Accepted: 07/06/2019] [Indexed: 12/27/2022] Open
Abstract
Centrosomes and primary cilia are usually considered as distinct organelles, although both are assembled with the same evolutionary conserved, microtubule-based templates, the centrioles. Centrosomes serve as major microtubule- and actin cytoskeleton-organizing centers and are involved in a variety of intracellular processes, whereas primary cilia receive and transduce environmental signals to elicit cellular and organismal responses. Understanding the functional relationship between centrosomes and primary cilia is important because defects in both structures have been implicated in various diseases, including cancer. Here, we discuss evidence that the animal centrosome evolved, with the transition to complex multicellularity, as a hybrid organelle comprised of the two distinct, but intertwined, structural-functional modules: the centriole/primary cilium module and the pericentriolar material/centrosome module. The evolution of the former module may have been caused by the expanding cellular diversification and intercommunication, whereas that of the latter module may have been driven by the increasing complexity of mitosis and the requirement for maintaining cell polarity, individuation, and adhesion. Through its unique ability to serve both as a plasma membrane-associated primary cilium organizer and a juxtanuclear microtubule-organizing center, the animal centrosome has become an ideal integrator of extracellular and intracellular signals with the cytoskeleton and a switch between the non-cell autonomous and the cell-autonomous signaling modes. In light of this hypothesis, we discuss centrosome dynamics during cell proliferation, migration, and differentiation and propose a model of centrosome-driven microtubule assembly in mitotic and interphase cells. In addition, we outline the evolutionary benefits of the animal centrosome and highlight the hierarchy and modularity of the centrosome biogenesis networks.
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Affiliation(s)
- Vladimir Joukov
- N.N. Petrov National Medical Research Center of Oncology, 197758 Saint-Petersburg, Russia.
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Cilia Distal Domain: Diversity in Evolutionarily Conserved Structures. Cells 2019; 8:cells8020160. [PMID: 30769894 PMCID: PMC6406257 DOI: 10.3390/cells8020160] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2018] [Revised: 01/25/2019] [Accepted: 02/13/2019] [Indexed: 12/12/2022] Open
Abstract
Eukaryotic cilia are microtubule-based organelles that protrude from the cell surface to fulfill sensory and motility functions. Their basic structure consists of an axoneme templated by a centriole/basal body. Striking differences in ciliary ultra-structures can be found at the ciliary base, the axoneme and the tip, not only throughout the eukaryotic tree of life, but within a single organism. Defects in cilia biogenesis and function are at the origin of human ciliopathies. This structural/functional diversity and its relationship with the etiology of these diseases is poorly understood. Some of the important events in cilia function occur at their distal domain, including cilia assembly/disassembly, IFT (intraflagellar transport) complexes' remodeling, and signal detection/transduction. How axonemal microtubules end at this domain varies with distinct cilia types, originating different tip architectures. Additionally, they show a high degree of dynamic behavior and are able to respond to different stimuli. The existence of microtubule-capping structures (caps) in certain types of cilia contributes to this diversity. It has been proposed that caps play a role in axoneme length control and stabilization, but their roles are still poorly understood. Here, we review the current knowledge on cilia structure diversity with a focus on the cilia distal domain and caps and discuss how they affect cilia structure and function.
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Lack of GAS2L2 Causes PCD by Impairing Cilia Orientation and Mucociliary Clearance. Am J Hum Genet 2019; 104:229-245. [PMID: 30665704 DOI: 10.1016/j.ajhg.2018.12.009] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Accepted: 12/14/2018] [Indexed: 01/01/2023] Open
Abstract
Primary ciliary dyskinesia (PCD) is a genetic disorder in which impaired ciliary function leads to chronic airway disease. Exome sequencing of a PCD subject identified an apparent homozygous frameshift variant, c.887_890delTAAG (p.Val296Glyfs∗13), in exon 5; this frameshift introduces a stop codon in amino acid 308 of the growth arrest-specific protein 2-like 2 (GAS2L2). Further genetic screening of unrelated PCD subjects identified a second proband with a compound heterozygous variant carrying the identical frameshift variant and a large deletion (c.867_∗343+1207del; p.?) starting in exon 5. Both individuals had clinical features of PCD but normal ciliary axoneme structure. In this research, using human nasal cells, mouse models, and X.laevis embryos, we show that GAS2L2 is abundant at the apical surface of ciliated cells, where it localizes with basal bodies, basal feet, rootlets, and actin filaments. Cultured GAS2L2-deficient nasal epithelial cells from one of the affected individuals showed defects in ciliary orientation and had an asynchronous and hyperkinetic (GAS2L2-deficient = 19.8 Hz versus control = 15.8 Hz) ciliary-beat pattern. These results were recapitulated in Gas2l2-/- mouse tracheal epithelial cell (mTEC) cultures and in X. laevis embryos treated with Gas2l2 morpholinos. In mice, the absence of Gas2l2 caused neonatal death, and the conditional deletion of Gas2l2 impaired mucociliary clearance (MCC) and led to mucus accumulation. These results show that a pathogenic variant in GAS2L2 causes a genetic defect in ciliary orientation and impairs MCC and results in PCD.
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Cenpj Regulates Cilia Disassembly and Neurogenesis in the Developing Mouse Cortex. J Neurosci 2019; 39:1994-2010. [PMID: 30626697 DOI: 10.1523/jneurosci.1849-18.2018] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 12/19/2018] [Accepted: 12/24/2018] [Indexed: 11/21/2022] Open
Abstract
Primary cilia are microtubule-based protuberances that project from the eukaryotic cell body to sense the extracellular environment. Ciliogenesis is closely correlated to the cell cycle and defects of cilia are related to human systemic diseases such as primary ciliary dyskinesia. However, the role of ciliogenesis in cortical development remains unclear. Here, we demonstrate that Cenpj, a protein that is required for centriole biogenesis, plays a role in regulating cilium disassembly in vivo Depletion of Cenpj in neural progenitor cells results in long cilia and abnormal cilia disassembly. Radial glial cells Cenpj depletion exhibit uncompleted cell division, reduced cell proliferation, and increased cell apoptosis in the developing mouse cerebrum cortex, leading to microcephaly. In addition, Cenpj depletion causes long and thin primary cilia and motile cilia in adult neural stem cells and reduced cell proliferation in the subventricular zone. Furthermore, we show that Cenpj regulates cilia disassembly and neurogenesis through Kif2a, a plus-end-directed motor protein. These data collected from mice of both sexes provide insights into how ciliogenesis plays roles in cortical development and how primary microcephaly is induced by Cenpj mutations in humans.SIGNIFICANCE STATEMENT Autosomal recessive primary microcephaly is a neurodevelopmental disorder with the major symptoms of reduction of circumference of the head, brain volume, and cortex thickness with normal brain architecture in birth. We used conditional Cenpj deletion mice and found that neural progenitor cells (NPCs) exhibited long primary cilia and abnormal cilium appendages. The defective cilium disassembly caused by Cenpj depletion might correlate to reduced cell proliferation, uncompleted cell division, cell apoptosis, and microcephaly in mice. Cenpj also regulates the cilium structure of adult neural stem cells and adult neurogenesis in mice. Additionally, our results illustrate that Cenpj regulates cilia disassembly and neurogenesis through Kif2a, indicating that primary cilia dynamics play a crucial role in NPC mitosis and adult neurogenesis.
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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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Shahid U, Singh P. Emerging Picture of Deuterosome-Dependent Centriole Amplification in MCCs. Cells 2018; 7:E152. [PMID: 30262752 PMCID: PMC6210342 DOI: 10.3390/cells7100152] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Revised: 09/20/2018] [Accepted: 09/25/2018] [Indexed: 12/26/2022] Open
Abstract
Multiciliated cells (MCCs) have several hair-like structures called cilia, which are required to propel substances on their surface. A cilium is organized from a basal body which resembles a hollow microtubule structure called a centriole. In terminally differentiated MCCs, hundreds of new basal bodies/centrioles are formed via two parallel pathways: the centriole- and deuterosome-dependent pathways. The deuterosome-dependent pathway is also referred to as "de novo" because unlike the centriole-dependent pathway which requires pre-existing centrioles, in the de novo pathway multiple new centrioles are organized around non-microtubule structures called deuterosomes. In the last five years, some deuterosome-specific markers have been identified and concurrent advancements in the super-resolution techniques have significantly contributed to gaining insights about the major stages of centriole amplification during ciliogenesis. Altogether, a new picture is emerging which also challenges the previous notion that deuterosome pathway is de novo. This review is primarily focused on studies that have contributed towards the better understanding of deuterosome-dependent centriole amplification and presents a developing model about the major stages identified during this process.
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Affiliation(s)
- Umama Shahid
- Department of Bioscience & Bioengineering, Indian Institute of Technology Jodhpur, NH 65, Nagour Road, Karwar 342037, India.
| | - Priyanka Singh
- Department of Bioscience & Bioengineering, Indian Institute of Technology Jodhpur, NH 65, Nagour Road, Karwar 342037, India.
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Mahen R. Stable centrosomal roots disentangle to allow interphase centriole independence. PLoS Biol 2018; 16:e2003998. [PMID: 29649211 PMCID: PMC5918241 DOI: 10.1371/journal.pbio.2003998] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2017] [Revised: 04/24/2018] [Accepted: 03/19/2018] [Indexed: 11/23/2022] Open
Abstract
The centrosome is a non-membrane-bound cellular compartment consisting of 2 centrioles surrounded by a protein coat termed the pericentriolar material (PCM). Centrioles generally remain physically associated together (a phenomenon called centrosome cohesion), yet how this occurs in the absence of a bounding lipid membrane is unclear. One model posits that pericentriolar fibres formed from rootletin protein directly link centrioles, yet little is known about the structure, biophysical properties, or assembly kinetics of such fibres. Here, I combine live-cell imaging of endogenously tagged rootletin with cell fusion and find previously unrecognised plasticity in centrosome cohesion. Rootletin forms large, diffusionally stable bifurcating fibres, which amass slowly on mature centrioles over many hours from anaphase. Nascent centrioles (procentrioles), in contrast, do not form roots and must be licensed to do so through polo-like kinase 1 (PLK1) activity. Transient separation of roots accompanies centriolar repositioning during the interphase, suggesting that centrioles organize as independent units, each containing discrete roots. Indeed, forced induction of duplicate centriole pairs allows independent reshuffling of individual centrioles between the pairs. Therefore collectively, these findings suggest that progressively nucleated polymers mediate the dynamic association of centrioles as either 1 or 2 interphase centrosomes, with implications for the understanding of how non-membrane-bound organelles self-organise.
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Affiliation(s)
- Robert Mahen
- Photonics Group, Department of Physics, Imperial College London, London, United Kingdom
- The Medical Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, Cambridge, United Kingdom
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41
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Zanini D, Giraldo D, Warren B, Katana R, Andrés M, Reddy S, Pauls S, Schwedhelm-Domeyer N, Geurten BR, Göpfert MC. Proprioceptive Opsin Functions in Drosophila Larval Locomotion. Neuron 2018; 98:67-74.e4. [DOI: 10.1016/j.neuron.2018.02.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2017] [Revised: 01/15/2018] [Accepted: 02/26/2018] [Indexed: 01/13/2023]
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C8ORF37 Is Required for Photoreceptor Outer Segment Disc Morphogenesis by Maintaining Outer Segment Membrane Protein Homeostasis. J Neurosci 2018; 38:3160-3176. [PMID: 29440555 DOI: 10.1523/jneurosci.2964-17.2018] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2017] [Revised: 01/30/2018] [Accepted: 02/05/2018] [Indexed: 01/09/2023] Open
Abstract
C8ORF37 is a causative gene for three different clinical forms of incurable retinal degeneration. However, the completely unknown function of C8ORF37 limits our understanding of the pathogenicity of C8ORF37 mutations. Here, we performed a comprehensive phenotypic characterization of a C8orf37 KO mouse line, generated using CRISPR/Cas9 technology. Both C8orf37 KO male and female mice exhibited progressive and simultaneous degeneration of rod and cone photoreceptors but no non-ocular phenotypes. The major ultrastructural feature of C8orf37 KO photoreceptors was massive disorganization of the outer segment (OS) membrane discs starting from the onset of disc morphogenesis during development. At the molecular level, the amounts of multiple OS-specific membrane proteins, including proteins involved in membrane disc organization, were reduced, although these proteins were targeted normally to the OS. Considering the distribution of C8ORF37 throughout the photoreceptor cell body, the normal structure of the KO photoreceptor connecting cilium, and the absence of defects in other ciliary organs of the KO mice, our findings do not support the previous notion that C8ORF37 was a ciliary protein. Because C8ORF37 is absent in the photoreceptor OS, C8ORF37 may participate in the secretory pathway of OS membrane proteins in the photoreceptor cell body and thus maintain the homeostasis of these proteins. This study established a valid animal model for future therapeutic studies of C8ORF37-associated retinal degeneration. This study also shed new light on the role of C8ORF37 in photoreceptors and on the pathogenic mechanism underlying retinal degeneration caused by C8ORF37 mutations.SIGNIFICANCE STATEMENT Inherited retinal degeneration is a group of incurable conditions with poorly understood underlying molecular mechanisms. We investigated C8ORF37, a causative gene for three retinal degenerative conditions: retinitis pigmentosa, cone-rod dystrophy, and Bardet-Biedl syndrome. C8ORF37 encodes a protein with no known functional domains and thus its biological function is unpredictable. We knocked out the C8ORF37 ortholog in mice, which resulted in a retinal phenotype similar to that observed in patients. We further demonstrated that C8ORF37 is required for photoreceptor outer segment disc formation and alignment, a process that is critical for photoreceptor function and survival. This study advances our understanding of the pathogenesis of retinal degeneration and establishes a valuable mouse model for future therapeutic development.
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Loncarek J, Bettencourt-Dias M. Building the right centriole for each cell type. J Cell Biol 2017; 217:823-835. [PMID: 29284667 PMCID: PMC5839779 DOI: 10.1083/jcb.201704093] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 09/14/2017] [Accepted: 11/27/2017] [Indexed: 12/22/2022] Open
Abstract
Loncarek and Bettencourt-Dias review molecular mechanisms of centriole biogenesis amongst different organisms and cell types. The centriole is a multifunctional structure that organizes centrosomes and cilia and is important for cell signaling, cell cycle progression, polarity, and motility. Defects in centriole number and structure are associated with human diseases including cancer and ciliopathies. Discovery of the centriole dates back to the 19th century. However, recent advances in genetic and biochemical tools, development of high-resolution microscopy, and identification of centriole components have accelerated our understanding of its assembly, function, evolution, and its role in human disease. The centriole is an evolutionarily conserved structure built from highly conserved proteins and is present in all branches of the eukaryotic tree of life. However, centriole number, size, and organization varies among different organisms and even cell types within a single organism, reflecting its cell type–specialized functions. In this review, we provide an overview of our current understanding of centriole biogenesis and how variations around the same theme generate alternatives for centriole formation and function.
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Affiliation(s)
- Jadranka Loncarek
- Cell Cycle Regulation Lab, Gulbenkian Institute of Science, Oeiras, Portugal
| | - Mónica Bettencourt-Dias
- Laboratory of Protein Dynamics and Signaling, National Institutes of Health/Center for Cancer Research/National Cancer Institute-Frederick, Frederick, MD
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Lewis TR, Zareba M, Link BA, Besharse JC. Cone myoid elongation involves unidirectional microtubule movement mediated by dynein-1. Mol Biol Cell 2017; 29:180-190. [PMID: 29142075 PMCID: PMC5909930 DOI: 10.1091/mbc.e17-08-0525] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Revised: 10/31/2017] [Accepted: 11/07/2017] [Indexed: 12/03/2022] Open
Abstract
Using structured illumination microscopy and photoconvertible tubulin in zebrafish photoreceptors, it is shown that microtubules move together during myoid elongation, a dark adaptive process in cone photoreceptors. Additionally, cytoplasmic dynein-1, localized at the base of the elongating myoid, mediates this unidirectional movement of microtubules. Teleosts and amphibians exhibit retinomotor movements, morphological changes in photoreceptors regulated by light and circadian rhythms. Cone myoid elongation occurs during dark adaptation, leading to the positioning of the cone outer segment closer to the retinal pigment epithelium. Although it has been shown that microtubules are essential for cone myoid elongation, the underlying mechanism has not been established. In this work, we generated a transgenic line of zebrafish expressing a photoconvertible form of α-tubulin (tdEOS-tubulin) specifically in cone photoreceptors. Using superresolution structured illumination microscopy in conjunction with both pharmacological and genetic manipulation, we show that cytoplasmic dynein-1, which localizes to the junction between the ellipsoid and myoid, functions to shuttle microtubules from the ellipsoid into the myoid during the course of myoid elongation. We propose a novel model by which stationary complexes of cytoplasmic dynein-1 are responsible for the shuttling of microtubules between the ellipsoid and myoid is the underlying force for the morphological change of myoid elongation.
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Affiliation(s)
- Tylor R Lewis
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Mariusz Zareba
- Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Brian A Link
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Joseph C Besharse
- Department of Cell Biology, Neurobiology, and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226 .,Department of Ophthalmology, Medical College of Wisconsin, Milwaukee, WI 53226
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45
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Bujakowska KM, Liu Q, Pierce EA. Photoreceptor Cilia and Retinal Ciliopathies. Cold Spring Harb Perspect Biol 2017; 9:cshperspect.a028274. [PMID: 28289063 DOI: 10.1101/cshperspect.a028274] [Citation(s) in RCA: 126] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Photoreceptors are sensory neurons designed to convert light stimuli into neurological responses. This process, called phototransduction, takes place in the outer segments (OS) of rod and cone photoreceptors. OS are specialized sensory cilia, with analogous structures to those present in other nonmotile cilia. Deficient morphogenesis and/or dysfunction of photoreceptor sensory cilia (PSC) caused by mutations in a variety of photoreceptor-specific and common cilia genes can lead to inherited retinal degenerations (IRDs). IRDs can manifest as isolated retinal diseases or syndromic diseases. In this review, we describe the structure and composition of PSC and different forms of ciliopathies with retinal involvement. We review the genetics of the IRDs, which are monogenic disorders but genetically diverse with regard to causality.
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Affiliation(s)
- Kinga M Bujakowska
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114
| | - Qin Liu
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114
| | - Eric A Pierce
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts 02114
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Potter C, Zhu W, Razafsky D, Ruzycki P, Kolesnikov AV, Doggett T, Kefalov VJ, Betleja E, Mahjoub MR, Hodzic D. Multiple Isoforms of Nesprin1 Are Integral Components of Ciliary Rootlets. Curr Biol 2017. [PMID: 28625779 DOI: 10.1016/j.cub.2017.05.066] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
SYNE1 (synaptic nuclear envelope 1) encodes multiple isoforms of Nesprin1 (nuclear envelope spectrin 1) that associate with the nuclear envelope (NE) through a C-terminal KASH (Klarsicht/Anc1/Syne homology) domain (Figure 1A) [1-4]. This domain interacts directly with the SUN (Sad1/Unc84) domain of Sun proteins [5-7], a family of transmembrane proteins of the inner nuclear membrane (INM) [8, 9], to form the so-called LINC complexes (linkers of the nucleoskeleton and cytoskeleton) that span the entire NE and mediate nuclear positioning [10-12]. In a stark departure from this classical depiction of Nesprin1 in the context of the NE, we report here that rootletin recruits Nesprin1α at the ciliary rootlets of photoreceptors and identify asymmetric NE aggregates of Nesprin1α and Sun2 that dock filaments of rootletin at the nuclear surface. In NIH 3T3 cells, we show that recombinant rootletin filaments also dock to the NE through the specific recruitment of an ∼600-kDa endogenous isoform of Nesprin1 (Nes1600kDa) and of Sun2. In agreement with the association of Nesprin1α with photoreceptor ciliary rootlets and the functional interaction between rootletin and Nesprin1 in fibroblasts, we demonstrate that multiple isoforms of Nesprin1 are integral components of ciliary rootlets of multiciliated ependymal and tracheal cells. Together, these data provide a novel functional paradigm for Nesprin1 at ciliary rootlets and suggest that the wide spectrum of human pathologies linked to truncating mutations of SYNE1 [13-15] may originate in part from ciliary defects.
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Affiliation(s)
- Chloe Potter
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | - Wanqiu Zhu
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | - David Razafsky
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | - Philip Ruzycki
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | - Alexander V Kolesnikov
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | - Teresa Doggett
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | - Vladimir J Kefalov
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | - Ewelina Betleja
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | - Moe R Mahjoub
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | - Didier Hodzic
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA.
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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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Flanagan AM, Stavenschi E, Basavaraju S, Gaboriau D, Hoey DA, Morrison CG. Centriole splitting caused by loss of the centrosomal linker protein C-NAP1 reduces centriolar satellite density and impedes centrosome amplification. Mol Biol Cell 2017; 28:736-745. [PMID: 28100636 PMCID: PMC5349781 DOI: 10.1091/mbc.e16-05-0325] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 12/24/2022] Open
Abstract
Duplication of the centrosomes is a tightly regulated process. Abnormal centrosome numbers can impair cell division and cause changes in how cells migrate. Duplicated centrosomes are held together by a proteinaceous linker made up of rootletin filaments anchored to the centrioles by C-NAP1. This linker is removed in a NEK2A kinase-dependent manner as mitosis begins. To explore C-NAP1 activities in regulating centrosome activities, we used genome editing to ablate it. C-NAP1-null cells were viable and had an increased frequency of premature centriole separation, accompanied by reduced density of the centriolar satellites, with reexpression of C-NAP1 rescuing both phenotypes. We found that the primary cilium, a signaling structure that arises from the mother centriole docked to the cell membrane, was intact in the absence of C-NAP1, although components of the ciliary rootlet were aberrantly localized away from the base of the cilium. C-NAP1-deficient cells were capable of signaling through the cilium, as determined by gene expression analysis after fluid flow-induced shear stress and the relocalization of components of the Hedgehog pathway. Centrosome amplification induced by DNA damage or by PLK4 or CDK2 overexpression was markedly reduced in the absence of C-NAP1. We conclude that centriole splitting reduces the local density of key centriolar precursors to impede overduplication.
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Affiliation(s)
- Anne-Marie Flanagan
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - Elena Stavenschi
- Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, and
- Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin, Dublin 2, Ireland
| | - Shivakumar Basavaraju
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - David Gaboriau
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
| | - David A Hoey
- Trinity Centre for Bioengineering, Trinity Biomedical Sciences Institute, and
- Department of Mechanical and Manufacturing Engineering, School of Engineering, Trinity College Dublin, Dublin 2, Ireland
- Advanced Materials and Bioengineering Research Centre, Trinity College Dublin, and Royal College of Surgeons in Ireland, Dublin 2, Ireland
| | - Ciaran G Morrison
- Centre for Chromosome Biology, School of Natural Sciences, National University of Ireland Galway, Galway, Ireland
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SHG-specificity of cellular Rootletin filaments enables naïve imaging with universal conservation. Sci Rep 2017; 7:39967. [PMID: 28059168 PMCID: PMC5216331 DOI: 10.1038/srep39967] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 11/30/2016] [Indexed: 02/01/2023] Open
Abstract
Despite growing demand for truly naïve imaging, label-free observation of cilium-related structure remains challenging, and validation of the pertinent molecules is correspondingly difficult. In this study, in retinas and cultured cells, we distinctively visualized Rootletin filaments in rootlets in the second harmonic generation (SHG) channel, integrated in custom coherent nonlinear optical microscopy (CNOM) with a simple, compact, and ultra-broadband supercontinuum light source. This SHG signal was primarily detected on rootlets of connecting cilia in the retinal photoreceptor and was validated by colocalization with anti-Rootletin staining. Transfection of cells with Rootletin fragments revealed that the SHG signal can be ascribed to filaments assembled from the R234 domain, but not to cross-striations assembled from the R123 domain. Consistent with this, Rootletin-depleted cells lacked SHG signal expected as centrosome linker. As a proof of concept, we confirmed that similar fibrous SHG was observed even in unicellular ciliates. These findings have potential for broad applications in clinical diagnosis and biophysical experiments with various organisms.
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Vertii A, Hehnly H, Doxsey S. The Centrosome, a Multitalented Renaissance Organelle. Cold Spring Harb Perspect Biol 2016; 8:8/12/a025049. [PMID: 27908937 DOI: 10.1101/cshperspect.a025049] [Citation(s) in RCA: 76] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The centrosome acts as a microtubule-organizing center (MTOC) from the G1 to G2 phases of the cell cycle; it can mature into a spindle pole during mitosis and/or transition into a cilium by elongating microtubules (MTs) from the basal body on cell differentiation or cell cycle arrest. New studies hint that the centrosome functions in more than MT organization. For instance, it has recently been shown that a specific substructure of the centrosome-the mother centriole appendages-are required for the recycling of endosomes back to the plasma membrane. This alone could have important implications for a renaissance in our understanding of the development of primary cilia, endosome recycling, and the immune response. Here, we review newly identified roles for the centrosome in directing membrane traffic, the immunological synapse, and the stress response.
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Affiliation(s)
- Anastassiia Vertii
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Heidi Hehnly
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
| | - Stephen Doxsey
- Program in Molecular Medicine, University of Massachusetts Medical School, Worcester, Massachusetts 01605
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