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McKay EJ, Luijten I, Broadway-Stringer S, Thomson A, Weng X, Gehmlich K, Gray GA, Semple RK. Female Alms1-deficient mice develop echocardiographic features of adult but not infantile Alström syndrome cardiomyopathy. Dis Model Mech 2024; 17:dmm050561. [PMID: 38756069 DOI: 10.1242/dmm.050561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 04/03/2024] [Indexed: 05/18/2024] Open
Abstract
Alström syndrome (AS), a multisystem disorder caused by biallelic ALMS1 mutations, features major early morbidity and mortality due to cardiac complications. The latter are biphasic, including infantile dilated cardiomyopathy and distinct adult-onset cardiomyopathy, and poorly understood. We assessed cardiac function of Alms1 knockout (KO) mice by echocardiography. Cardiac function was unaltered in Alms1 global KO mice of both sexes at postnatal day 15 (P15) and 8 weeks. At 23 weeks, female - but not male - KO mice showed increased left atrial area and decreased isovolumic relaxation time, consistent with early restrictive cardiomyopathy, as well as reduced ejection fraction. No histological or transcriptional changes were seen in myocardium of 23-week-old female Alms1 global KO mice. Female mice with Pdgfra-Cre-driven Alms1 deletion in cardiac fibroblasts and in a small proportion of cardiomyocytes did not recapitulate the phenotype of global KO at 23 weeks. In conclusion, only female Alms1-deficient adult mice show echocardiographic evidence of cardiac dysfunction, consistent with the cardiomyopathy of AS. The explanation for sexual dimorphism remains unclear but might involve metabolic or endocrine differences between sexes.
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Affiliation(s)
- Eleanor J McKay
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Ineke Luijten
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | | | - Adrian Thomson
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Xiong Weng
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Katya Gehmlich
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham B15 2TT, UK
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine and British Heart Foundation Centre of Research Excellence Oxford, University of Oxford, Oxford OX3 9DU, UK
| | - Gillian A Gray
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Robert K Semple
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, UK
- MRC Human Genetics Unit, Institute of Genetics and Cancer, University of Edinburgh, Edinburgh EH4 2XU, UK
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Hanaki K, Kinoshita T, Fujimoto M, Sonoyama-Kawashima Y, Kanzaki S, Namba N. Alström Syndrome: A Review Focusing on Its Diverse Clinical Manifestations and Their Etiology as a Ciliopathy. Yonago Acta Med 2024; 67:93-99. [PMID: 38803594 PMCID: PMC11128078 DOI: 10.33160/yam.2024.05.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Accepted: 05/08/2024] [Indexed: 05/29/2024]
Abstract
Alström syndrome is a form of inherited obesity caused by a single gene abnormality and is inherited as an autosomal recessive trait. It is characterised by a variety of clinical manifestations, including progressive visual and hearing impairment, type 2 diabetes mellitus, dilated cardiomyopathy, and hepatic and renal dysfunction, in addition to obesity. Recent insights underline the pivotal involvement of the disease-associated gene (ALMS1) in cilia formation and function, leading to the classification of its clinical manifestations as a ciliopathy. This review delineates the diverse clinical indicators defining the syndrome and elucidates its pathological underpinnings.
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Affiliation(s)
- Keiichi Hanaki
- School of Health Sciences, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan
- Division of Perinatology and Pediatrics, Department of Multidisciplinary Internal Medicine, School of Medicine, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan
| | - Tomoe Kinoshita
- Division of Perinatology and Pediatrics, Department of Multidisciplinary Internal Medicine, School of Medicine, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan
- Division of Pediatrics, Tottori Red Cross Hospital, Tottori 680-8517, Japan
| | - Masanobu Fujimoto
- Division of Perinatology and Pediatrics, Department of Multidisciplinary Internal Medicine, School of Medicine, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan
| | - Yuki Sonoyama-Kawashima
- Division of Perinatology and Pediatrics, Department of Multidisciplinary Internal Medicine, School of Medicine, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan
- Department of Pediatrics, Shimane University Faculty of Medicine, Izumo 693-8501, Japan
| | - Susumu Kanzaki
- Division of Perinatology and Pediatrics, Department of Multidisciplinary Internal Medicine, School of Medicine, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan
- Asahigawasou Rehabilitation and Medical Center, Okayama 703-8555, Japan
| | - Noriyuki Namba
- Division of Perinatology and Pediatrics, Department of Multidisciplinary Internal Medicine, School of Medicine, Faculty of Medicine, Tottori University, Yonago 683-8503, Japan
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Woerz F, Hoffmann F, Antony S, Bolz S, Jarboui MA, Junger K, Klose F, Stehle IF, Boldt K, Ueffing M, Beyer T. Interactome Analysis Reveals a Link of the Novel ALMS1-CEP70 Complex to Centrosomal Clusters. Mol Cell Proteomics 2024; 23:100701. [PMID: 38122899 PMCID: PMC10820798 DOI: 10.1016/j.mcpro.2023.100701] [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: 06/02/2023] [Revised: 11/08/2023] [Accepted: 12/17/2023] [Indexed: 12/23/2023] Open
Abstract
Alström syndrome (ALMS) is a very rare autosomal-recessive disorder, causing a broad range of clinical defects most notably retinal degeneration, type 2 diabetes, and truncal obesity. The ALMS1 gene encodes a complex and huge ∼0.5 MDa protein, which has hampered analysis in the past. The ALMS1 protein is localized to the centrioles and the basal body of cilia and is involved in signaling processes, for example, TGF-β signaling. However, the exact molecular function of ALMS1 at the basal body remains elusive and controversial. We recently demonstrated that protein complex analysis utilizing endogenously tagged cells provides an excellent tool to investigate protein interactions of ciliary proteins. Here, CRISPR/Cas9-mediated endogenously tagged ALMS1 cells were used for affinity-based protein complex analysis. Centrosomal and microtubule-associated proteins were identified, which are potential regulators of ALMS1 function, such as the centrosomal protein 70 kDa (CEP70). Candidate proteins were further investigated in ALMS1-deficient hTERT-RPE1 cells. Loss of ALMS1 led to shortened cilia with no change in structural protein localization, for example, acetylated and ɣ-tubulin, Centrin-3, or the novel interactor CEP70. Conversely, reduction of CEP70 resulted in decreased ALMS1 at the ciliary basal body. Complex analysis of CEP70 revealed domain-specific ALMS1 interaction involving the TPR-containing C-terminal (TRP-CT) fragment of CEP70. In addition to ALMS1, several ciliary proteins, including CEP135, were found to specifically bind to the TPR-CT domain. Data are available via ProteomeXchange with the identifier PXD046401. Protein interactors identified in this study provide candidate lists that help to understand ALMS1 and CEP70 function in cilia-related protein modification, cell death, and disease-related mechanisms.
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Affiliation(s)
- Franziska Woerz
- Eberhard Karls University Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
| | - Felix Hoffmann
- Eberhard Karls University Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Shibu Antony
- Eberhard Karls University Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Sylvia Bolz
- Eberhard Karls University Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Mohamed Ali Jarboui
- Eberhard Karls University Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Katrin Junger
- Eberhard Karls University Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Franziska Klose
- Eberhard Karls University Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Isabel F Stehle
- Eberhard Karls University Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Karsten Boldt
- Eberhard Karls University Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Marius Ueffing
- Eberhard Karls University Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Tina Beyer
- Eberhard Karls University Tübingen, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany.
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Bea-Mascato B, Gómez-Castañeda E, Sánchez-Corrales YE, Castellano S, Valverde D. Loss of the centrosomal protein ALMS1 alters lipid metabolism and the regulation of extracellular matrix-related processes. Biol Direct 2023; 18:84. [PMID: 38062477 PMCID: PMC10704752 DOI: 10.1186/s13062-023-00441-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Accepted: 11/27/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Alström syndrome (ALMS) is a rare autosomal recessive disease that is associated with mutations in ALMS1 gene. The main clinical manifestations of ALMS are retinal dystrophy, obesity, type 2 diabetes mellitus, dilated cardiomyopathy and multi-organ fibrosis, characteristic in kidneys and liver. Depletion of the protein encoded by ALMS1 has been associated with the alteration of different processes regulated via the primary cilium, such as the NOTCH or TGF-β signalling pathways. However, the cellular impact of these deregulated pathways in the absence of ALMS1 remains unknown. METHODS In this study, we integrated RNA-seq and proteomic analysis to determine the gene expression profile of hTERT-BJ-5ta ALMS1 knockout fibroblasts after TGF-β stimulation. In addition, we studied alterations in cross-signalling between the TGF-β pathway and the AKT pathway in this cell line. RESULTS We found that ALMS1 depletion affects the TGF-β pathway and its cross-signalling with other pathways such as PI3K/AKT, EGFR1 or p53. In addition, alterations associated with ALMS1 depletion clustered around the processes of extracellular matrix regulation and lipid metabolism in both the transcriptome and proteome. By studying the enriched pathways of common genes differentially expressed in the transcriptome and proteome, collagen fibril organisation, β-oxidation of fatty acids and eicosanoid metabolism emerged as key processes altered by the absence of ALMS1. Finally, an overactivation of the AKT pathway was determined in the absence of ALMS1 that could be explained by a decrease in PTEN gene expression. CONCLUSION ALMS1 deficiency disrupts cross-signalling between the TGF-β pathway and other dependent pathways in hTERT-BJ-5ta cells. Furthermore, altered cross-signalling impacts the regulation of extracellular matrix-related processes and fatty acid metabolism, and leads to over-activation of the AKT pathway.
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Affiliation(s)
- Brais Bea-Mascato
- CINBIO Facultad de Biología, Universidad de Vigo, Campus As Lagoas-Marcosende s/n, Vigo, 36310, Spain
- Grupo de Investigación en Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - Eduardo Gómez-Castañeda
- Molecular and Cellular Immunology Section, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Yara E Sánchez-Corrales
- Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Sergi Castellano
- Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, University College London, London, UK
- Zayed Centre for Research into Rare Disease in Children, UCL Genomics, University College London, London, UK
| | - Diana Valverde
- CINBIO Facultad de Biología, Universidad de Vigo, Campus As Lagoas-Marcosende s/n, Vigo, 36310, Spain.
- Grupo de Investigación en Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain.
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Stephenson EJ, Kinney CE, Stayton AS, Han JC. Energy expenditure deficits drive obesity in a mouse model of Alström syndrome. Obesity (Silver Spring) 2023; 31:2786-2798. [PMID: 37712194 DOI: 10.1002/oby.23877] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2023] [Accepted: 06/27/2023] [Indexed: 09/16/2023]
Abstract
OBJECTIVE Alström syndrome (AS) is a rare multisystem disorder of which early onset childhood obesity is a cardinal feature. Like humans with AS, animal models with Alms1 loss-of-function mutations develop obesity, supporting the notion that ALMS1 is required for the regulatory control of energy balance across species. This study aimed to determine which component(s) of energy balance are reliant on ALMS1. METHODS Comprehensive energy balance phenotyping was performed on Alms1tvrm102 mice at both 8 and 18 weeks of age. RESULTS It was found that adiposity gains occurred early and rapidly in Alms1tvrm102 male mice but much later in females. Rapid increases in body fat in males were due to a marked reduction in energy expenditure (EE) during early life and not due to any genotype-specific increases in energy intake under chow conditions. Energy intake did increase in a genotype-specific manner when mice were provided a high-fat diet, exacerbating the effects of reduced EE on obesity progression. The EE deficit observed in male Alms1tvrm102 mice did not persist as mice aged. CONCLUSIONS Either loss of ALMS1 causes a developmental delay in the mechanisms controlling early life EE or activation of compensatory mechanisms occurs after obesity is established in AS. Future studies will determine how ALMS1 modulates EE and how sex moderates this process.
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Affiliation(s)
- Erin J Stephenson
- Department of Anatomy, College of Graduate Studies and Chicago College of Osteopathic Medicine, Midwestern University, Downers Grove, Illinois, USA
- Department of Pediatrics, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, Tennessee, USA
| | - Clint E Kinney
- Department of Pediatrics, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, Tennessee, USA
| | - Amanda S Stayton
- Department of Pediatrics, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, Tennessee, USA
- Department of Surgery, College of Medicine, James D. Eason Transplant Institute, University of Tennessee Health Science Center, Memphis, Tennessee, USA
| | - Joan C Han
- Department of Pediatrics, College of Medicine, University of Tennessee Health Science Center, Memphis, Tennessee, USA
- Children's Foundation Research Institute, Le Bonheur Children's Hospital, Memphis, Tennessee, USA
- Department of Pediatrics, Icahn School of Medicine at Mount Sinai and Kravis Children's Hospital, New York, New York, USA
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6
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Guimaraes TACD, Arram E, Shakarchi AF, Georgiou M, Michaelides M. Inherited causes of combined vision and hearing loss: clinical features and molecular genetics. Br J Ophthalmol 2023; 107:1403-1414. [PMID: 36162969 DOI: 10.1136/bjo-2022-321790] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Accepted: 09/07/2022] [Indexed: 11/04/2022]
Abstract
Combined vision and hearing loss, also known as dual sensory impairment, can occur in several genetic conditions, including ciliopathies such as Usher and Bardet-Biedl syndrome, mitochondrial DNA disorders and systemic diseases, such as CHARGE, Stickler, Waardenburg, Alport and Alstrom syndrome. The retinal phenotype may point to the diagnosis of such disorders. Herein, we aim to provide a comprehensive review of the molecular genetics and clinical features of the most common non-chromosomal inherited disorders to cause dual sensory impairment.
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Affiliation(s)
| | - Elizabeth Arram
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- UCL Institute of Ophthalmology, University College London, London, UK
| | - Ahmed F Shakarchi
- Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Michalis Georgiou
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- UCL Institute of Ophthalmology, University College London, London, UK
- Jones Eye Institute, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Michel Michaelides
- Moorfields Eye Hospital NHS Foundation Trust, London, UK
- UCL Institute of Ophthalmology, University College London, London, UK
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Erickson T, Biggers WP, Williams K, Butland SE, Venuto A. Regionalized Protein Localization Domains in the Zebrafish Hair Cell Kinocilium. J Dev Biol 2023; 11:28. [PMID: 37367482 DOI: 10.3390/jdb11020028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Revised: 05/05/2023] [Accepted: 06/02/2023] [Indexed: 06/28/2023] Open
Abstract
Sensory hair cells are the receptors for auditory, vestibular, and lateral line sensory organs in vertebrates. These cells are distinguished by "hair"-like projections from their apical surface collectively known as the hair bundle. Along with the staircase arrangement of the actin-filled stereocilia, the hair bundle features a single, non-motile, true cilium called the kinocilium. The kinocilium plays an important role in bundle development and the mechanics of sensory detection. To understand more about kinocilial development and structure, we performed a transcriptomic analysis of zebrafish hair cells to identify cilia-associated genes that have yet to be characterized in hair cells. In this study, we focused on three such genes-ankef1a, odf3l2a, and saxo2-because human or mouse orthologs are either associated with sensorineural hearing loss or are located near uncharacterized deafness loci. We made transgenic fish that express fluorescently tagged versions of their proteins, demonstrating their localization to the kinocilia of zebrafish hair cells. Furthermore, we found that Ankef1a, Odf3l2a, and Saxo2 exhibit distinct localization patterns along the length of the kinocilium and within the cell body. Lastly, we have reported a novel overexpression phenotype of Saxo2. Overall, these results suggest that the hair cell kinocilium in zebrafish is regionalized along its proximal-distal axis and set the groundwork to understand more about the roles of these kinocilial proteins in hair cells.
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Affiliation(s)
- Timothy Erickson
- Department of Biology, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
| | | | - Kevin Williams
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Shyanne E Butland
- Department of Biology, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
| | - Alexandra Venuto
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
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Bea-Mascato B, Neira-Goyanes E, Iglesias-Rodríguez A, Valverde D. Depletion of ALMS1 affects TGF-β signalling pathway and downstream processes such as cell migration and adhesion capacity. Front Mol Biosci 2022; 9:992313. [PMID: 36325276 PMCID: PMC9621122 DOI: 10.3389/fmolb.2022.992313] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 09/13/2022] [Indexed: 12/23/2023] Open
Abstract
Background: ALMS1 is a ubiquitous gene associated with Alström syndrome (ALMS). The main symptoms of ALMS affect multiple organs and tissues, generating at last, multi-organic fibrosis in the lungs, kidneys and liver. TGF-β is one of the main pathways implicated in fibrosis, controlling the cell cycle, apoptosis, cell migration, cell adhesion and epithelial-mesenchymal transition (EMT). Nevertheless, the role of ALMS1 gene in fibrosis generation and other implicated processes such as cell migration or cell adhesion via the TGF- β pathway has not been elucidated yet. Methods: Initially, we evaluated how depletion of ALMS1 affects different processes like apoptosis, cell cycle and mitochondrial activity in HeLa cells. Then, we performed proteomic profiling with TGF-β stimuli in HeLa ALMS1 -/- cells and validated the results by examining different EMT biomarkers using qPCR. The expression of these EMT biomarkers were also studied in hTERT-BJ-5ta ALMS1 -/-. Finally, we evaluated the SMAD3 and SMAD2 phosphorylation and cell migration capacity in both models. Results: Depletion of ALMS1 generated apoptosis resistance to thapsigargin (THAP) and C2-Ceramide (C2-C), and G2/M cell cycle arrest in HeLa cells. For mitochondrial activity, results did not show significant differences between ALMS1 +/+ and ALMS1 -/-. Proteomic results showed inhibition of downstream pathways regulated by TGF-β. The protein-coding genes (PCG) were associated with processes like focal adhesion or cell-substrate adherens junction in HeLa. SNAI1 showed an opposite pattern to what would be expected when activating the EMT in HeLa and BJ-5ta. Finally, in BJ-5ta model a reduced activation of SMAD3 but not SMAD2 were also observed. In HeLa model no alterations in the canonical TGF-β pathway were observed but both cell lines showed a reduction in migration capacity. Conclusion: ALMS1 has a role in controlling the cell cycle and the apoptosis processes. Moreover, the depletion of ALMS1 affects the signal transduction through the TGF-β and other processes like the cell migration and adhesion capacity.
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Affiliation(s)
- Brais Bea-Mascato
- CINBIO, Universidad de Vigo, Vigo, Spain
- Grupo de Investigación en Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - Elena Neira-Goyanes
- CINBIO, Universidad de Vigo, Vigo, Spain
- Grupo de Investigación en Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - Antía Iglesias-Rodríguez
- CINBIO, Universidad de Vigo, Vigo, Spain
- Grupo de Investigación en Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
| | - Diana Valverde
- CINBIO, Universidad de Vigo, Vigo, Spain
- Grupo de Investigación en Enfermedades Raras y Medicina Pediátrica, Instituto de Investigación Sanitaria Galicia Sur (IIS Galicia Sur), SERGAS-UVIGO, Vigo, Spain
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9
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Hearing Loss in Adults With Alström Syndrome-Experience From the UK National Alström Service. Otol Neurotol 2022; 43:e620-e627. [PMID: 35761454 DOI: 10.1097/mao.0000000000003553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To characterize the patterns of hearing loss and methods of hearing rehabilitation in the UK national cohort of adults with Alström syndrome. STUDY DESIGN Retrospective review of electronic patient records. SETTING UK National multi-disciplinary team (MDT) Alström service held at the Queen Elizabeth Hospital, Birmingham. PATIENTS Forty one adult patients with a diagnosis of Alström syndrome, confirmed via ALMS1 gene sequencing, are under ongoing review within the UK National MDT Alström service. MAIN OUTCOME MEASURES Magnitude and type of hearing loss were analyzed using patients' audiometric data. Deterioration of hearing was calculated using serial pure tone audiograms. Methods of hearing rehabilitation used by patients and potential candidacy for cochlear implantation were analyzed. RESULTS Of 34 patients with available audiograms, all had sensorineural hearing loss (SNHL). Dual sensory (visual and hearing) loss was present in 32/34 (94%) patients. Hearing deteriorated with advancing age, at 1.23 dB/yr. Severe- profound SNHL was present in 9/34 (26%) cases. Air conduction hearing aids were used in 27/34 (79%) cases, and cochlear implants in 2/34 (5%). CONCLUSIONS Alström syndrome is an ultra-rare genetic disorder with progressive, debilitating multi-system manifestations, including SNHL. The UK National MDT Alström service represents one of the largest reported adult cohorts in the world. SNHL in this group was ubiquitous, showing a rapid decline in hearing with age. Annual audiometric assessment to enable early diagnosis of hearing loss and optimum rehabilitation are paramount to minimize the impact of hearing loss in this condition.
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Xu R, Zhou H, Fang F, Qiu L, Liu X. A novel variant site of Alstrom syndrome in a Chinese child: a case report. Transl Pediatr 2022; 11:595-600. [PMID: 35558973 PMCID: PMC9085953 DOI: 10.21037/tp-21-535] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 02/24/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND Alstrom syndrome (ALMS) is an ultra-rare multisystem genetic disorder caused by autosomal recessive inheritance of the ALMS1 gene. It manifests as multisystem dysfunction, displaying unique clinical signs and symptoms and various severity, which may lead to delayed prognosis or misdiagnosis in medical practice. Although almost 300 pathogenic variants have been reported, there are some variant sites that have not been recognized yet. CASE DESCRIPTION We report a case of a 14-year-old boy with manifestations, including binocular vision loss, acanthosis nigricans, type 2 diabetes, insulin resistance, elevated transaminase, hepatic fibrosis, and proteinuria. Compound heterozygous variants in the ALMS1 gene have been discovered by whole exon sequencing. One of his variant sites was C. 8158C>T, which was from his father. And the other variant site was C. 3575C>A, which was from his mother. To the great of our knowledge, this site has not been reported before. Both of the variants make the synthesis of the peptide chain terminated in advance and an incomplete polypeptide chain is formed. CONCLUSIONS The clinical presentations of ALMS are complicated and varied. Although early diagnosis can be made according to typical clinical symptoms, whole exon sequencing is necessary for the diagnosis of ALMS, as indicated by our study.
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Affiliation(s)
- Rongrong Xu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hua Zhou
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Feng Fang
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Liru Qiu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xinglou Liu
- Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Shi H, Wang H, Zhang C, Lu Y, Yao J, Chen Z, Xing G, Wei Q, Cao X. Mutations in OSBPL2 cause hearing loss associated with primary cilia defects via Sonic Hedgehog signaling. JCI Insight 2022; 7:149626. [PMID: 35041619 PMCID: PMC8876550 DOI: 10.1172/jci.insight.149626] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 01/12/2022] [Indexed: 11/17/2022] Open
Abstract
Defective primary cilia cause a range of diseases called ciliopathies, which include hearing loss (HL). Variants in the human oxysterol-binding protein like 2 (OSBPL2/ORP2) are responsible for autosomal dominant nonsyndromic HL (DFNA67). However, the pathogenesis of OSBPL2 deficiency has not been fully elucidated. In this study, we show that the Osbpl2-KO mice exhibited progressive HL and abnormal cochlear development with defective cilia. Further research revealed that OSBPL2 was located at the base of the kinocilia in hair cells (HCs) and primary cilia in supporting cells (SCs) and functioned in the maintenance of ciliogenesis by regulating the homeostasis of PI(4,5)P2 (phosphatidylinositol 4,5-bisphosphate) on the cilia membrane. OSBPL2 deficiency led to a significant increase of PI(4,5)P2 on the cilia membrane, which could be partially rescued by the overexpression of INPP5E. In addition, smoothened and GL13, the key molecules in the Sonic Hedgehog (Shh) signaling pathway, were detected to be downregulated in Osbpl2-KO HEI-OC1 cells. Our findings revealed that OSBPL2 deficiency resulted in ciliary defects and abnormal Shh signaling transduction in auditory cells, which helped to elucidate the underlying mechanism of OSBPL2 deficiency in HL.
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Affiliation(s)
- Hairong Shi
- Department of Medical Genetics, Nanjing Medical Univeristy, Nanjing, China
| | - Hongshun Wang
- Department of Medical Genetics, Nanjing Medical Univeristy, Nanjing, China
| | - Cheng Zhang
- Department of Medical Genetics, Nanjing Medical Univeristy, Nanjing, China
| | - Yajie Lu
- Department of Medical Genetics, Nanjing Medical Univeristy, Nanjing, China
| | - Jun Yao
- Department of Medical Genetics, Nanjing Medical Univeristy, Nanjing, China
| | - Zhibin Chen
- Department of Otolaryngology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Guangqian Xing
- Department of Otolaryngology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Qinjun Wei
- Department of Medical Genetics, Nanjing Medical Univeristy, Nanjing, China
| | - Xin Cao
- Department of Medical Genetics, Nanjing Medical Univeristy, Nanjing, China
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12
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Pablos M, Casanueva-Álvarez E, González-Casimiro CM, Merino B, Perdomo G, Cózar-Castellano I. Primary Cilia in Pancreatic β- and α-Cells: Time to Revisit the Role of Insulin-Degrading Enzyme. Front Endocrinol (Lausanne) 2022; 13:922825. [PMID: 35832432 PMCID: PMC9271624 DOI: 10.3389/fendo.2022.922825] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 05/24/2022] [Indexed: 12/25/2022] Open
Abstract
The primary cilium is a narrow organelle located at the surface of the cell in contact with the extracellular environment. Once underappreciated, now is thought to efficiently sense external environmental cues and mediate cell-to-cell communication, because many receptors, ion channels, and signaling molecules are highly or differentially expressed in primary cilium. Rare genetic disorders that affect cilia integrity and function, such as Bardet-Biedl syndrome and Alström syndrome, have awoken interest in studying the biology of cilium. In this review, we discuss recent evidence suggesting emerging roles of primary cilium and cilia-mediated signaling pathways in the regulation of pancreatic β- and α-cell functions, and its implications in regulating glucose homeostasis.
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Affiliation(s)
- Marta Pablos
- Department of Biochemistry, Molecular Biology and Physiology, School of Medicine, University of Valladolid, Valladolid, Spain
- *Correspondence: Marta Pablos,
| | - Elena Casanueva-Álvarez
- Unidad de Excelencia Instituto de Biología y Genética Molecular, University of Valladolid Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain
| | - Carlos M. González-Casimiro
- Unidad de Excelencia Instituto de Biología y Genética Molecular, University of Valladolid Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain
| | - Beatriz Merino
- Unidad de Excelencia Instituto de Biología y Genética Molecular, University of Valladolid Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain
| | - Germán Perdomo
- Unidad de Excelencia Instituto de Biología y Genética Molecular, University of Valladolid Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain
| | - Irene Cózar-Castellano
- Department of Biochemistry, Molecular Biology and Physiology, School of Medicine, University of Valladolid, Valladolid, Spain
- Unidad de Excelencia Instituto de Biología y Genética Molecular, University of Valladolid Consejo Superior de Investigaciones Científicas (CSIC), Valladolid, Spain
- Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Madrid, Spain
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13
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Lyu J, Qian X, Chen B, Ren D. Methods to Investigate Cell Polarity of Inner Ear. Methods Mol Biol 2022; 2438:251-275. [PMID: 35147947 DOI: 10.1007/978-1-0716-2035-9_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Hair cells in cochlea and vestibular organs depend on the coordinated cell polarity to perform the normal auditory or balance function. The mouse inner ear is one of the ideal model to study planar cell polarity. In this chapter, we introduce a series of general experimental methods for studying planar cell polarity in the inner ear. The approaches presented here are also applicable to other organs with particular polarity phenotypes.
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Affiliation(s)
- Jihan Lyu
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Xiaoqing Qian
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Binjun Chen
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China
| | - Dongdong Ren
- ENT institute and Department of Otorhinolaryngology, Eye & ENT Hospital, Fudan University, Shanghai, China.
- NHC Key Laboratory of Hearing Medicine (Fudan University), Shanghai, China.
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14
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Hilgendorf KI. Primary Cilia Are Critical Regulators of White Adipose Tissue Expansion. Front Physiol 2021; 12:769367. [PMID: 34759842 PMCID: PMC8573240 DOI: 10.3389/fphys.2021.769367] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Accepted: 10/04/2021] [Indexed: 12/14/2022] Open
Abstract
The primary cilium is a microtubule-based cellular protrusion found on most mammalian cell types in diverse tissues. It functions as a cellular antenna to sense and transduce a broad range of signals, including odorants, light, mechanical stimuli, and chemical ligands. This diversity in signals requires cilia to display a context and cell type-specific repertoire of receptors. Recently, primary cilia have emerged as critical regulators of metabolism. The importance of primary cilia in metabolic disease is highlighted by the clinical features of human genetic disorders with dysfunctional ciliary signaling, which include obesity and diabetes. This review summarizes the current literature on the role of primary cilia in metabolic disease, focusing on the importance of primary cilia in directing white adipose tissue expansion during obesity.
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Affiliation(s)
- Keren I Hilgendorf
- Department of Biochemistry, University of Utah School of Medicine, Salt Lake City, UT, United States
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15
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Wang D, Zhou J. The Kinocilia of Cochlear Hair Cells: Structures, Functions, and Diseases. Front Cell Dev Biol 2021; 9:715037. [PMID: 34422834 PMCID: PMC8374625 DOI: 10.3389/fcell.2021.715037] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Accepted: 07/14/2021] [Indexed: 12/11/2022] Open
Abstract
Primary cilia are evolutionarily conserved and highly specialized organelles that protrude from cell membranes. Mutations in genes encoding ciliary proteins can cause structural and functional ciliary defects and consequently multiple diseases, collectively termed ciliopathies. The mammalian auditory system is responsible for perceiving external sound stimuli that are ultimately processed in the brain through a series of physical and biochemical reactions. Here we review the structure and function of the specialized primary cilia of hair cells, termed kinocilia, found in the mammalian auditory system. We also discuss areas that might prove amenable for therapeutic management of auditory ciliopathies.
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Affiliation(s)
- Difei Wang
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China
| | - Jun Zhou
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin, China
- Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, China
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16
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Eintracht J, Forsythe E, May-Simera H, Moosajee M. Translational readthrough of ciliopathy genes BBS2 and ALMS1 restores protein, ciliogenesis and function in patient fibroblasts. EBioMedicine 2021; 70:103515. [PMID: 34365092 PMCID: PMC8353411 DOI: 10.1016/j.ebiom.2021.103515] [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: 04/23/2021] [Revised: 07/13/2021] [Accepted: 07/19/2021] [Indexed: 12/04/2022] Open
Abstract
BACKGROUND Ciliary dysfunction underlies a range of genetic disorders collectively termed ciliopathies, for which there are no treatments available. Bardet-Biedl syndrome (BBS) is characterised by multisystemic involvement, including rod-cone dystrophy and renal abnormalities. Together with Alström syndrome (AS), they are known as the 'obesity ciliopathies' due to their common phenotype. Nonsense mutations are responsible for approximately 11% and 40% of BBS and AS cases, respectively. Translational readthrough inducing drugs (TRIDs) can restore full-length protein bypassing in-frame premature termination codons, and are a potential therapeutic approach for nonsense-mediated ciliopathies. METHODS Patient fibroblasts harbouring nonsense mutations from two different ciliopathies (Bardet-Biedl Syndrome and Alström Syndrome) were treated with PTC124 (ataluren) or amlexanox. Following treatment, gene expression, protein levels and ciliogenesis were evaluated. The expression of intraflagellar transport protein IFT88 and G-protein coupled receptor SSTR3 was investigated as a readout of ciliary function. FINDINGS mRNA expression was significantly increased in amlexanox-treated patient fibroblasts, and full-length BBS2 or ALMS1 protein expression was restored in PTC124- and amlexanox-treated fibroblasts. Treatment with TRIDs significantly improved ciliogenesis defects in BBS2Y24*/R275* fibroblasts. Treatment recovered IFT88 expression and corrected SSTR3 mislocalisation in BBS2Y24*/R275* and ALMS1S1645*/S1645* fibroblasts, suggesting rescue of ciliary function. INTERPRETATION The recovery of full-length BBS2 and ALMS1 expression and correction of anatomical and functional ciliary defects in BBS2Y24*/R275* and ALMS1S1645*/S1645* fibroblasts suggest TRIDs are a potential therapeutic option for the treatment of nonsense-mediated ciliopathies. FUNDING Wellcome Trust 205174/Z/16/Z, National Centre for the Replacement, Refinement & Reduction of Animals in Research. Deutsche Forschungsgemeinschaft SPP2127 (DFG Grant MA 6139/3-1).
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Affiliation(s)
| | - Elizabeth Forsythe
- Clinical Genetics Unit, Great Ormond Street Hospital; Genetics and Genomic Medicine Programme, Great Ormond Street Institute of Child Health
| | - Helen May-Simera
- Institute of Molecular Physiology, Johannes Gutenburg University, Mainz
| | - Mariya Moosajee
- UCL Institute of Ophthalmology, London, United Kingdom; The Francis Crick Institute, London, United Kingdom; Moorfields Eye Hospital NHS Foundation Trust, London, United Kingdom; Great Ormond Street Hospital for Children NHS Foundation Trust, London, United Kingdom.
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17
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Zhang JJ, Wang JQ, Sun MQ, Xu D, Xiao Y, Lu WL, Dong ZY. Alström syndrome with a novel mutation of ALMS1 and Graves’ hyperthyroidism: A case report and review of the literature. World J Clin Cases 2021; 9:3200-3211. [PMID: 33969109 PMCID: PMC8080750 DOI: 10.12998/wjcc.v9.i13.3200] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/21/2021] [Accepted: 02/08/2021] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Alström syndrome (AS, OMIM ID 203800) is a rare disease involving multiple organs in children and is mostly reported in non-Chinese patients. In the Chinese population, there are few reports on the clinical manifestations and pathogenesis of AS. This is the first report on the association between AS and Graves’ hyperthyroidism.
CASE SUMMARY An 8-year-old Chinese girl was diagnosed with AS. Two years later, Graves’ hyperthyroidism developed with progressive liver dysfunction. The patient’s clinical data were collected; DNA from peripheral blood of the proband, parents and sibling was collected for gene mutation detection using the second-generation sequencing method and gene panel for diabetes. The association between the patient’s genotype and clinical phenotype was analyzed. She carried the pathogenic compound heterozygous mutation of ALMS1 (c.2296_2299del4 and c.11460C>A). These stop-gain mutations likely caused truncation of the ALMS1 protein.
CONCLUSION The manifestation of hyperthyroidism may suggest rapid progression of AS.
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Affiliation(s)
- Juan-Juan Zhang
- Department of Pediatrics, Ruijin Hospital, Shanghai Jiao-Tong University, School of Medicine, Shanghai 200025, China
| | - Jun-Qi Wang
- Department of Pediatrics, Ruijin Hospital, Shanghai Jiao-Tong University, School of Medicine, Shanghai 200025, China
| | - Man-Qing Sun
- Department of Pediatrics, Ruijin Hospital, Shanghai Jiao-Tong University, School of Medicine, Shanghai 200025, China
| | - De Xu
- Department of Pediatrics, Ruijin Hospital, Shanghai Jiao-Tong University, School of Medicine, Shanghai 200025, China
| | - Yuan Xiao
- Department of Pediatrics, Ruijin Hospital, Shanghai Jiao-Tong University, School of Medicine, Shanghai 200025, China
| | - Wen-Li Lu
- Department of Pediatrics, Ruijin Hospital, Shanghai Jiao-Tong University, School of Medicine, Shanghai 200025, China
| | - Zhi-Ya Dong
- Department of Pediatrics, Ruijin Hospital, Shanghai Jiao-Tong University, School of Medicine, Shanghai 200025, China
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18
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Landin Malt A, Clancy S, Hwang D, Liu A, Smith C, Smith M, Hatley M, Clemens C, Lu X. Non-Canonical Wnt Signaling Regulates Cochlear Outgrowth and Planar Cell Polarity via Gsk3β Inhibition. Front Cell Dev Biol 2021; 9:649830. [PMID: 33937247 PMCID: PMC8086559 DOI: 10.3389/fcell.2021.649830] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/17/2021] [Indexed: 11/26/2022] Open
Abstract
During development, sensory hair cells (HCs) in the cochlea assemble a stereociliary hair bundle on their apical surface with planar polarized structure and orientation. We have recently identified a non-canonical, Wnt/G-protein/PI3K signaling pathway that promotes cochlear outgrowth and coordinates planar polarization of the HC apical cytoskeleton and alignment of HC orientation across the cochlear epithelium. Here, we determined the involvement of the kinase Gsk3β and the small GTPase Rac1 in non-canonical Wnt signaling and its regulation of the planar cell polarity (PCP) pathway in the cochlea. We provided the first in vivo evidence for Wnt regulation of Gsk3β activity via inhibitory Ser9 phosphorylation. Furthermore, we carried out genetic rescue experiments of cochlear defects caused by blocking Wnt secretion. We showed that cochlear outgrowth was partially rescued by genetic ablation of Gsk3β but not by expression of stabilized β-catenin; while PCP defects, including hair bundle polarity and junctional localization of the core PCP proteins Fzd6 and Dvl2, were partially rescued by either Gsk3β ablation or constitutive activation of Rac1. Our results identify Gsk3β and likely Rac1 as downstream components of non-canonical Wnt signaling and mediators of cochlear outgrowth, HC planar polarity, and localization of a subset of core PCP proteins in the cochlea.
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Affiliation(s)
- Andre Landin Malt
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA, United States
| | - Shaylyn Clancy
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA, United States
| | - Diane Hwang
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA, United States
| | - Alice Liu
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA, United States
| | - Connor Smith
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA, United States
| | - Margaret Smith
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA, United States
| | - Maya Hatley
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA, United States
| | - Christopher Clemens
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA, United States
| | - Xiaowei Lu
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA, United States
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19
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Parkinson L, Stawicki TM. alms1 mutant zebrafish do not show hair cell phenotypes seen in other cilia mutants. PLoS One 2021; 16:e0246844. [PMID: 33793549 PMCID: PMC8016283 DOI: 10.1371/journal.pone.0246844] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 01/26/2021] [Indexed: 11/18/2022] Open
Abstract
Multiple cilia-associated genes have been shown to affect hair cells in zebrafish (Danio rerio), including the human deafness gene dcdc2, the radial spoke gene rsph9, and multiple intraflagellar transport (IFT) and transition zone genes. Recently a zebrafish alms1 mutant was generated. The ALMS1 gene is the gene mutated in the ciliopathy Alström Syndrome a disease that causes hearing loss among other symptoms. The hearing loss seen in Alström Syndrome may be due in part to hair cell defects as Alms1 mutant mice show stereocilia polarity defects and a loss of hair cells. Hair cell loss is also seen in postmortem analysis of Alström patients. The zebrafish alms1 mutant has metabolic defects similar to those seen in Alström syndrome and Alms1 mutant mice. We wished to investigate if it also had hair cell defects. We, however, failed to find any hair cell related phenotypes in alms1 mutant zebrafish. They had normal lateral line hair cell numbers as both larvae and adults and normal kinocilia formation. They also showed grossly normal swimming behavior, response to vibrational stimuli, and FM1-43 loading. Mutants also showed a normal degree of sensitivity to both short-term neomycin and long-term gentamicin treatment. These results indicate that cilia-associated genes differentially affect different hair cell types.
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Affiliation(s)
- Lauren Parkinson
- Neuroscience Program, Lafayette College, Easton, Pennsylvania, United States of America
| | - Tamara M. Stawicki
- Neuroscience Program, Lafayette College, Easton, Pennsylvania, United States of America
- * E-mail:
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20
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Moon KH, Ma JH, Min H, Koo H, Kim H, Ko HW, Bok J. Dysregulation of sonic hedgehog signaling causes hearing loss in ciliopathy mouse models. eLife 2020; 9:56551. [PMID: 33382037 PMCID: PMC7806262 DOI: 10.7554/elife.56551] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 12/31/2020] [Indexed: 12/11/2022] Open
Abstract
Defective primary cilia cause a range of diseases known as ciliopathies, including hearing loss. The etiology of hearing loss in ciliopathies, however, remains unclear. We analyzed cochleae from three ciliopathy mouse models exhibiting different ciliogenesis defects: Intraflagellar transport 88 (Ift88), Tbc1d32 (a.k.a. bromi), and Cilk1 (a.k.a. Ick) mutants. These mutants showed multiple developmental defects including shortened cochlear duct and abnormal apical patterning of the organ of Corti. Although ciliogenic defects in cochlear hair cells such as misalignment of the kinocilium are often associated with the planar cell polarity pathway, our results showed that inner ear defects in these mutants are primarily due to loss of sonic hedgehog signaling. Furthermore, an inner ear-specific deletion of Cilk1 elicits low-frequency hearing loss attributable to cellular changes in apical cochlear identity that is dedicated to low-frequency sound detection. This type of hearing loss may account for hearing deficits in some patients with ciliopathies.
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Affiliation(s)
- Kyeong-Hye Moon
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea.,BK21 PLUS project for Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Ji-Hyun Ma
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hyehyun Min
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Heiyeun Koo
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea.,BK21 PLUS project for Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - HongKyung Kim
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Hyuk Wan Ko
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul, Republic of Korea
| | - Jinwoong Bok
- Department of Anatomy, Yonsei University College of Medicine, Seoul, Republic of Korea.,BK21 PLUS project for Medical Science, Yonsei University College of Medicine, Seoul, Republic of Korea.,Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Republic of Korea
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21
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Brücker L, Kretschmer V, May-Simera HL. The entangled relationship between cilia and actin. Int J Biochem Cell Biol 2020; 129:105877. [PMID: 33166678 DOI: 10.1016/j.biocel.2020.105877] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/23/2020] [Accepted: 10/26/2020] [Indexed: 12/14/2022]
Abstract
Primary cilia are microtubule-based sensory cell organelles that are vital for tissue and organ development. They act as an antenna, receiving and transducing signals, enabling communication between cells. Defects in ciliogenesis result in severe genetic disorders collectively termed ciliopathies. In recent years, the importance of the direct and indirect involvement of actin regulators in ciliogenesis came into focus as it was shown that F-actin polymerisation impacts ciliation. The ciliary basal body was further identified as both a microtubule and actin organising centre. In the current review, we summarize recent studies on F-actin in and around primary cilia, focusing on different actin regulators and their effect on ciliogenesis, from the initial steps of basal body positioning and regulation of ciliary assembly and disassembly. Since primary cilia are also involved in several intracellular signalling pathways such as planar cell polarity (PCP), subsequently affecting actin rearrangements, the multiple effectors of this pathway are highlighted in more detail with a focus on the feedback loops connecting actin networks and cilia proteins. Finally, we elucidate the role of actin regulators in the development of ciliopathy symptoms and cancer.
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Affiliation(s)
- Lena Brücker
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, Germany
| | - Viola Kretschmer
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, Germany
| | - Helen Louise May-Simera
- Cilia Cell Biology, Institute of Molecular Physiology, Johannes-Gutenberg University, Mainz, Germany.
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22
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Association between ALMS 1 variants and early-onset coronary artery disease: a case-control study in Chinese population. Biosci Rep 2020; 40:226133. [PMID: 32808654 PMCID: PMC7463302 DOI: 10.1042/bsr20193637] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Revised: 08/08/2020] [Accepted: 08/13/2020] [Indexed: 12/17/2022] Open
Abstract
Background: Genome-wide linkage analysis revealed the polymorphism of rs6748040 and glutamic acid repeat are potential pathogenic factors of early-onset myocardial infarction (MI). The present study was designed to investigate the associations of Alström syndrome 1 (ALMS 1) gene in Chinese populations with early-onset coronary artery disease (CAD). Methods: The two variants of the ALMS 1 gene were genotyped in 1252 early-onset CAD patients and 1378 controls using PCR, followed by Sml I restriction enzyme digestion or direct sequencing of the PCR product. The associations were estimated using the odds ratio (OR) and the 95% confidence interval (CI). Results: A significant association between the ALMS 1 G/A variant and the risk of early-onset MI was detected in G vs.A (OR = 1.371, 95% CI: 1.183–1.589), GG vs. AA (OR = 2.037, 95% CI: 1.408–2.948), dominant genetic model (OR = 1.794, 95% CI: 1.254–2.567), and recessive genetic model (OR = 1.421, 95% CI: 1.177–1.716). 14 glutamic acid repeat (A14) is risk factor for early-onset MI (OR = 1.605, 95% CI: 1.313–1.962) and 17 glutamic acid repeat (A17) is protective factor for the disease (OR = 0.684, 95% CI: 0.601–0.827). These associations were not detected in early-onset CAD patients. Conclusions: Our findings indicated that G/A variant (rs6748040) and glutamic acid repeat polymorphism of the ALMS 1 gene associated with the risk of early-onset MI in the Chinese population.
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23
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Engle SE, Bansal R, Antonellis PJ, Berbari NF. Cilia signaling and obesity. Semin Cell Dev Biol 2020; 110:43-50. [PMID: 32466971 DOI: 10.1016/j.semcdb.2020.05.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Revised: 05/08/2020] [Accepted: 05/10/2020] [Indexed: 12/11/2022]
Abstract
An emerging number of rare genetic disorders termed ciliopathies are associated with pediatric obesity. It is becoming clear that the mechanisms associated with cilia dysfunction and obesity in these syndromes are complex. In addition to ciliopathic syndromic forms of obesity, several cilia-associated signaling gene mutations also lead to morbid obesity. While cilia have critical and diverse functions in energy homeostasis including their roles in centrally mediated food intake as well as in peripheral tissues, many questions remain. Here, we briefly discuss the syndromic ciliopathies and monoallelic cilia signaling gene mutations associated with obesity. We also describe potential ways cilia may be involved in common obesity. We discuss how neuronal cilia impact food intake potentially through leptin signaling and changes in ciliary G protein-coupled receptor (GPCR) signaling. We highlight several recent studies that have implicated the potential for cilia in peripheral tissues such as adipose and the pancreas to contribute to metabolic dysfunction. Then we discuss the potential for cilia to impact energy homeostasis through their roles in both development and adult tissue homeostasis. The studies discussed in this review highlight how a comprehensive understanding of the requirement of cilia for the regulation of diverse biological functions will contribute to our understanding of common forms of obesity.
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Affiliation(s)
- Staci E Engle
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Ruchi Bansal
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Patrick J Antonellis
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA
| | - Nicolas F Berbari
- Department of Biology, Indiana University-Purdue University Indianapolis, Indianapolis, IN, USA; Stark Neurosciences Research Institute, Indiana University, Indianapolis, IN, USA; Center for Diabetes and Metabolic Diseases, Indiana University School of Medicine, Indianapolis, IN, USA.
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Pazour GJ, Quarmby L, Smith AO, Desai PB, Schmidts M. Cilia in cystic kidney and other diseases. Cell Signal 2019; 69:109519. [PMID: 31881326 DOI: 10.1016/j.cellsig.2019.109519] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 12/21/2019] [Accepted: 12/21/2019] [Indexed: 12/23/2022]
Abstract
Epithelial cells lining the ducts and tubules of the kidney nephron and collecting duct have a single non-motile cilium projecting from their surface into the lumen of the tubule. These organelles were long considered vestigial remnants left as a result of evolution from a ciliated ancestor, but we now recognize them as critical sensory antennae. In the kidney, the polycystins and fibrocystin, products of the major human polycystic kidney disease genes, localize to this organelle. The polycystins and fibrocystin, through an unknown mechanism, monitor the diameter of the kidney tubules and regulate the proliferation and differentiation of the cells lining the tubule. When the polycystins, fibrocystin or cilia themselves are defective, the cell perceives this as a pro-proliferative signal, which leads to tubule dilation and cystic disease. In addition to critical roles in preventing cyst formation in the kidney, cilia are also important in cystic and fibrotic diseases of the liver and pancreas, and ciliary defects lead to a variety of developmental abnormalities that cause structural birth defects in most organs.
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Affiliation(s)
- Gregory J Pazour
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Suite 213, 373 Plantation Street, Worcester, MA 01605, United States of America.
| | - Lynne Quarmby
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
| | - Abigail O Smith
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Suite 213, 373 Plantation Street, Worcester, MA 01605, United States of America
| | - Paurav B Desai
- Program in Molecular Medicine, University of Massachusetts Medical School, Biotech II, Suite 213, 373 Plantation Street, Worcester, MA 01605, United States of America
| | - Miriam Schmidts
- Center for Pediatrics and Adolescent Medicine, University Hospital Freiburg, Freiburg University Faculty of Medicine, Mathildenstrasse 1, 79112 Freiburg, Germany.
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Lodh S. Primary Cilium, An Unsung Hero in Maintaining Functional β-cell Population. THE YALE JOURNAL OF BIOLOGY AND MEDICINE 2019; 92:471-480. [PMID: 31543709 PMCID: PMC6747938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
A primary challenge in type 2 diabetes (T2D) is the preservation of a functional population of β-cells, which play a central role in regulating blood glucose levels. Two congenital disorders, Bardet-Biedl syndrome (BBS) and Alström syndrome (ALMS), can serve as useful models to understand how β-cells are normally produced and regenerated. Both are characterized by obesity, loss of β-cells, and defects in primary cilia - the sensory center of cells. Primary cilia are cellular protrusions present in almost every vertebrate cell. This antenna-like organelle plays a crucial role in regulating several signaling pathways that direct proper development, proliferation, and homeostasis. Mutations in genes expressing ciliary proteins or proteins present at or near the base of the cilium lead to disorders, collectively called ciliopathies. BBS and Alström syndrome are such disorders. Though both BBS and Alström patients are obese, their childhood diabetes rates are vastly different, suggesting distinct pathogenesis underlying these two ciliopathies. Clinical studies suggest that BBS patients are protected against early onset diabetes by sustained or enhanced β-cell function. In contrast, Alström patients are more prone to develop diabetes. They have hyperinsulinemia, yet their β-cells fail to sense glucose and to regulate insulin secretion accordingly. These data suggest a potential role for primary cilia in maintaining a functional β-cell population and that defects in cilia or in ciliary proteins impair development and function of β-cells. Identifying the respective roles of primary cilia and ciliary proteins, such as BBS and ALMS1 may shed light on β-cell biology and uncover potentially novel targets for diabetes therapy.
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Affiliation(s)
- Sukanya Lodh
- To whom all correspondence should be addressed: Sukanya Lodh, Department of Biological sciences, Marquette University, 1428 W. Clybourn St., Milwaukee, WI 53233; Tel: 802-881-6221, Email address:
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26
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Tarchini B, Lu X. New insights into regulation and function of planar polarity in the inner ear. Neurosci Lett 2019; 709:134373. [PMID: 31295539 PMCID: PMC6732021 DOI: 10.1016/j.neulet.2019.134373] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 07/02/2019] [Accepted: 07/06/2019] [Indexed: 12/18/2022]
Abstract
Acquisition of cell polarity generates signaling and cytoskeletal asymmetry and thus underpins polarized cell behaviors during tissue morphogenesis. In epithelial tissues, both apical-basal polarity and planar polarity, which refers to cell polarization along an axis orthogonal to the apical-basal axis, are essential for epithelial morphogenesis and function. A prime example of epithelial planar polarity can be found in the auditory sensory epithelium (or organ of Corti, OC). Sensory hair cells, the sound receptors, acquire a planar polarized apical cytoskeleton which is uniformely oriented along an axis orthogonal to the longitudinal axis of the cochlear duct. Both cell-intrinsic and tissue-level planar polarity are necessary for proper perception of sound. Here we review recent insights into the novel roles and mechanisms of planar polarity signaling gained from genetic analysis in mice, focusing mainly on the OC but also with some discussions on the vestibular sensory epithelia.
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Affiliation(s)
- Basile Tarchini
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA; Department of Medicine, Tufts University, Boston, 02111, MA, USA; Graduate School of Biomedical Science and Engineering (GSBSE), University of Maine, Orono, 04469, ME, USA.
| | - Xiaowei Lu
- Department of Cell Biology, University of Virginia Health System, Charlottesville, VA, 22908, USA.
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27
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Girardet L, Augière C, Asselin MP, Belleannée C. Primary cilia: biosensors of the male reproductive tract. Andrology 2019; 7:588-602. [PMID: 31131532 DOI: 10.1111/andr.12650] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 04/16/2019] [Accepted: 04/17/2019] [Indexed: 12/21/2022]
Abstract
BACKGROUND The primary cilium is a microtubule-based organelle that extends transiently from the apical cell surface to act as a sensory antenna. Initially viewed as a cellular appendage of obscure significance, the primary cilium is now acknowledged as a key coordinator of signaling pathways during development and in tissue homeostasis. OBJECTIVES The aim of this review was to present the structure and function of this overlooked organelle,with an emphasis on its epididymal context and contribution to male infertility issues. MATERIALS AND METHODS A systematic review has been performed in order to include main references relevant to the aforementioned topic. RESULTS Increasing evidence demonstrates that primary cilia dysfunctions are associated with impaired male reproductive system development and male infertility issues. DISCUSSION While a large amount of data exists regarding the role of primary cilia in most organs and tissues, few studies investigated the contribution of these organelles to male reproductive tract development and homeostasis. CONCLUSION Functional studies of primary cilia constitute an emergent and exciting new area in reproductive biology research.
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Affiliation(s)
- Laura Girardet
- Department of Obstetrics, Gynecology and Reproduction, Université Laval, CHU de Québec Research Center (CHUL), Quebec City, QC, Canada
| | - Céline Augière
- Department of Obstetrics, Gynecology and Reproduction, Université Laval, CHU de Québec Research Center (CHUL), Quebec City, QC, Canada
| | - Marie-Pier Asselin
- Department of Obstetrics, Gynecology and Reproduction, Université Laval, CHU de Québec Research Center (CHUL), Quebec City, QC, Canada
| | - Clémence Belleannée
- Department of Obstetrics, Gynecology and Reproduction, Université Laval, CHU de Québec Research Center (CHUL), Quebec City, QC, Canada
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Stawicki TM, Linbo T, Hernandez L, Parkinson L, Bellefeuille D, Rubel EW, Raible DW. The role of retrograde intraflagellar transport genes in aminoglycoside-induced hair cell death. Biol Open 2019; 8:bio.038745. [PMID: 30578252 PMCID: PMC6361216 DOI: 10.1242/bio.038745] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Sensory hair cells are susceptible to numerous insults, including certain therapeutic medications like aminoglycoside antibiotics, and hearing and balance disorders are often a dose-limiting side effect of these medications. We show that mutations in multiple genes in both the retrograde intraflagellar transport (IFT) motor and adaptor complexes lead to resistance to aminoglycoside-induced hair cell death. These mutations also lead to defects in the entry of both aminoglycosides and the vital dye FM1-43 into hair cells, both processes that depend on hair cell mechanotransduction activity. However, the trafficking of proteins important for mechanotransduction activity is not altered by these mutations. Our data suggest that both retrograde IFT motor and adaptor complex genes are playing a role in aminoglycoside toxicity through affecting aminoglycoside uptake into hair cells. Summary: Here we show that both retrograde intraflagellar transport motor proteins and IFT-A adaptor molecules play a role in aminoglycoside-induced hair cell death, seemingly through regulating aminoglycoside uptake.
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Affiliation(s)
- Tamara M Stawicki
- Program in Neuroscience, Lafayette College, Easton, PA 18042, USA .,Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Tor Linbo
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Liana Hernandez
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA
| | - Lauren Parkinson
- Program in Neuroscience, Lafayette College, Easton, PA 18042, USA
| | | | - Edwin W Rubel
- Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, WA 98195, USA
| | - David W Raible
- Department of Biological Structure, University of Washington, Seattle, WA 98195, USA.,Virginia Merrill Bloedel Hearing Research Center, University of Washington, Seattle, WA 98195, USA
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Hearn T. ALMS1 and Alström syndrome: a recessive form of metabolic, neurosensory and cardiac deficits. J Mol Med (Berl) 2018; 97:1-17. [PMID: 30421101 PMCID: PMC6327082 DOI: 10.1007/s00109-018-1714-x] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2018] [Revised: 10/25/2018] [Accepted: 10/30/2018] [Indexed: 12/12/2022]
Abstract
Alström syndrome (AS) is characterised by metabolic deficits, retinal dystrophy, sensorineural hearing loss, dilated cardiomyopathy and multi-organ fibrosis. Elucidating the function of the mutated gene, ALMS1, is critical for the development of specific treatments and may uncover pathways relevant to a range of other disorders including common forms of obesity and type 2 diabetes. Interest in ALMS1 is heightened by the recent discovery of its involvement in neonatal cardiomyocyte cell cycle arrest, a process with potential relevance to regenerative medicine. ALMS1 encodes a ~ 0.5 megadalton protein that localises to the base of centrioles. Some studies have suggested a role for this protein in maintaining centriole-nucleated sensory organelles termed primary cilia, and AS is now considered to belong to the growing class of human genetic disorders linked to ciliary dysfunction (ciliopathies). However, mechanistic details are lacking, and recent studies have implicated ALMS1 in several processes including endosomal trafficking, actin organisation, maintenance of centrosome cohesion and transcription. In line with a more complex picture, multiple isoforms of the protein likely exist and non-centrosomal sites of localisation have been reported. This review outlines the evidence for both ciliary and extra-ciliary functions of ALMS1.
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Affiliation(s)
- Tom Hearn
- Institute of Life Science, Swansea University Medical School, Singleton Park, Swansea, SA2 8PP, UK.
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30
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Avenarius MR, Jung JY, Askew C, Jones SM, Hunker KL, Azaiez H, Rehman AU, Schraders M, Najmabadi H, Kremer H, Smith RJH, Géléoc GSG, Dolan DF, Raphael Y, Kohrman DC. Grxcr2 is required for stereocilia morphogenesis in the cochlea. PLoS One 2018; 13:e0201713. [PMID: 30157177 PMCID: PMC6114524 DOI: 10.1371/journal.pone.0201713] [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: 05/22/2018] [Accepted: 07/22/2018] [Indexed: 11/18/2022] Open
Abstract
Hearing and balance depend upon the precise morphogenesis and mechanosensory function of stereocilia, the specialized structures on the apical surface of sensory hair cells in the inner ear. Previous studies of Grxcr1 mutant mice indicated a critical role for this gene in control of stereocilia dimensions during development. In this study, we analyzed expression of the paralog Grxcr2 in the mouse and evaluated auditory and vestibular function of strains carrying targeted mutations of the gene. Peak expression of Grxcr2 occurs during early postnatal development of the inner ear and GRXCR2 is localized to stereocilia in both the cochlea and in vestibular organs. Homozygous Grxcr2 deletion mutants exhibit significant hearing loss by 3 weeks of age that is associated with developmental defects in stereocilia bundle orientation and organization. Despite these bundle defects, the mechanotransduction apparatus assembles in relatively normal fashion as determined by whole cell electrophysiological evaluation and FM1-43 uptake. Although Grxcr2 mutants do not exhibit overt vestibular dysfunction, evaluation of vestibular evoked potentials revealed subtle defects of the mutants in response to linear accelerations. In addition, reduced Grxcr2 expression in a hypomorphic mutant strain is associated with progressive hearing loss and bundle defects. The stereocilia localization of GRXCR2, together with the bundle pathologies observed in the mutants, indicate that GRXCR2 plays an intrinsic role in bundle orientation, organization, and sensory function in the inner ear during development and at maturity.
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Affiliation(s)
- Matthew R. Avenarius
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Jae-Yun Jung
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Charles Askew
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, United States of America
- Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Sherri M. Jones
- Department of Communication Sciences and Disorders, East Carolina University, Greenville, North Carolina, United States of America
| | - Kristina L. Hunker
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Hela Azaiez
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Atteeq U. Rehman
- Section on Human Genetics, Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Rockville, Maryland, United States of America
| | - Margit Schraders
- Hearing & Genes Division, Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Hossein Najmabadi
- Genetics Research Center, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
| | - Hannie Kremer
- Hearing & Genes Division, Department of Otorhinolaryngology, Radboud University Medical Center, Nijmegen, The Netherlands
- Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Nijmegen, The Netherlands
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, The Netherlands
| | - Richard J. H. Smith
- Molecular Otolaryngology and Renal Research Laboratories, Carver College of Medicine, University of Iowa, Iowa City, Iowa, United States of America
| | - Gwenaëlle S. G. Géléoc
- Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts, United States of America
| | - David F. Dolan
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Yehoash Raphael
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - David C. Kohrman
- Department of Otolaryngology/Kresge Hearing Research Institute, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- Department of Human Genetics, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
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Kılınç S, Yücel-Yılmaz D, Ardagil A, Apaydın S, Valverde D, Özgül RK, Güven A. Five novel ALMS1 gene mutations in six patients with Alström syndrome. J Pediatr Endocrinol Metab 2018; 31:681-687. [PMID: 29715191 DOI: 10.1515/jpem-2017-0418] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 03/12/2018] [Indexed: 12/19/2022]
Abstract
BACKGROUND Alström syndrome is a rare autosomal recessive inherited disorder caused by mutations in the ALMS1 gene. METHODS We describe the clinical and five novel mutational screening findings in six patients with Alström syndrome from five families in a single center with distinct clinical presentations of this condition. RESULTS Five novel mutations in ALMS1 in exon 8 and intron 17 were identified, one of them was a compound heterozygous: c.2259_2260insT, p.Glu754*; c.2035C>T p.Arg679*; c.2259_2260insT, p.Glu754*; c.5969C>G, p.Ser1990*; c.6541C>T, p. Gln2181*/c.11666-2A>G, splicing. One patient had gallstones, this association, to our knowledge, has not been reported in Alström syndrome previously. CONCLUSIONS Early diagnosis of Alström syndrome is often difficult in children and adolescents, because many of the clinical features develop over time. Early diagnosis can initiate an effective managemen of this condition, and it will help to reduce future damage.
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Affiliation(s)
- Suna Kılınç
- Department of Pediatric Endocrinology, Göztepe Education and Research Hospital, Pediatric Endocrinology Clinic, Istanbul, Turkey
| | - Didem Yücel-Yılmaz
- Hacettepe University, Institute of Child Health, Department of Pediatric Metabolism, Ankara, Turkey
| | - Aylin Ardagil
- Department of Ophthalmology, Göztepe Education and Research Hospital, Ophthalmology Clinics, Istanbul, Turkey
| | - Süheyla Apaydın
- Department of Nephrology, Nephrologist, Bakirkoy Sadi Konuk Education and Research Hospital, Nephrology Clinics, Istanbul, Turkey
| | - Diana Valverde
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Pontevedra, Spain
| | - Rıza Köksal Özgül
- Hacettepe University, Institute of Child Health, Department of Pediatric Metabolism, Ankara, Turkey
| | - Ayla Güven
- Zeynep Kamil Kadın ve Çocuk Hastalıkları Eğitim ve Araştırma Hastanesi, Dr. Burhanettin Üstünel sokak, 34668, Üsküdar, Istanbul, Turkey, Phone: +905322380300
- Pediatric Endocrinologist, Göztepe Education and Research Hospital, Pediatric Endocrinology Clinic, Istanbul, Turkey
- Amasya University Medical Faculty, Department of Pediatrics, Amasya, Turkey
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32
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Geets E, Meuwissen MEC, Van Hul W. Clinical, molecular genetics and therapeutic aspects of syndromic obesity. Clin Genet 2018; 95:23-40. [PMID: 29700824 DOI: 10.1111/cge.13367] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 04/05/2018] [Accepted: 04/16/2018] [Indexed: 12/13/2022]
Abstract
Obesity has become a major health problem worldwide. To date, more than 25 different syndromic forms of obesity are known in which one (monogenic) or multiple (polygenic) genes are involved. This review gives an overview of these forms and focuses more in detail on 6 syndromes: Prader Willi Syndrome and Prader Willi like phenotype, Bardet Biedl Syndrome, Alström Syndrome, Wilms tumor, Aniridia, Genitourinary malformations and mental Retardation syndrome and 16p11.2 (micro)deletions. Years of research provided plenty of information on the molecular genetics of these disorders and the obesity phenotype leading to a more individualized treatment of the symptoms, however, many questions still remain unanswered. As these obesity syndromes have different signs and symptoms in common, it makes it difficult to accurately diagnose patients which may result in inappropriate treatment of the disease. Therefore, the big challenge for clinicians and scientists is to more clearly differentiate all syndromic forms of obesity to provide conclusive genetic explanations and eventually deliver accurate genetic counseling and treatment. In addition, further delineation of the (functions of the) underlying genes with the use of array- or next-generation sequencing-based technology will be helpful to unravel the mechanisms of energy metabolism in the general population.
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Affiliation(s)
- E Geets
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - M E C Meuwissen
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
| | - W Van Hul
- Department of Medical Genetics, University of Antwerp and Antwerp University Hospital, Antwerp, Belgium
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Goodman L, Zallocchi M. Integrin α8 and Pcdh15 act as a complex to regulate cilia biogenesis in sensory cells. J Cell Sci 2017; 130:3698-3712. [PMID: 28883094 DOI: 10.1242/jcs.206201] [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] [Received: 05/15/2017] [Accepted: 09/01/2017] [Indexed: 01/21/2023] Open
Abstract
The way an organism perceives its surroundings depends on sensory systems and the highly specialized cilia present in the neurosensory cells. Here, we describe the existence of an integrin α8 (Itga8) and protocadherin-15a (Pcdh15a) ciliary complex in neuromast hair cells in a zebrafish model. Depletion of the complex via downregulation or loss-of-function mutation leads to a dysregulation of cilia biogenesis and endocytosis. At the molecular level, removal of the complex blocks the access of Rab8a into the cilia as well as normal recruitment of ciliary cargo by centriolar satellites. These defects can be reversed by the introduction of a constitutively active form of Rhoa, suggesting that Itga8-Pcdh15a complex mediates its effect through the activation of this small GTPase and probably by the regulation of actin cytoskeleton dynamics. Our data points to a novel mechanism involved in the regulation of sensory cilia development, with the corresponding implications for normal sensory function.
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Affiliation(s)
- Linda Goodman
- Center for Sensory Neuroscience, Boys Town National Research Hospital, Omaha, NE 68131, USA
| | - Marisa Zallocchi
- Center for Sensory Neuroscience, Boys Town National Research Hospital, Omaha, NE 68131, USA
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Lindsey S, Brewer C, Stakhovskaya O, Kim HJ, Zalewski C, Bryant J, King KA, Naggert JK, Gahl WA, Marshall JD, Gunay-Aygun M. Auditory and otologic profile of Alström syndrome: Comprehensive single center data on 38 patients. Am J Med Genet A 2017; 173:2210-2218. [PMID: 28573831 PMCID: PMC5526054 DOI: 10.1002/ajmg.a.38316] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 04/19/2017] [Accepted: 05/16/2017] [Indexed: 12/17/2022]
Abstract
Alström syndrome (AS) is a rare autosomal recessive ciliopathy caused by mutations in the ALMS1 gene. Hallmark characteristics include childhood onset of severe retinal degeneration, sensorineural hearing loss, obesity, insulin-resistant diabetes, and cardiomyopathy. Here we comprehensively characterize the auditory and otologic manifestations in a prospective case series of 38 individuals, aged 1.7-37.9 years, with genetically confirmed AS. Hearing loss was preceded by retinal dystrophy in all cases, and had an average age of detection of 7.45 years (range 1.5-15). Audiometric assessments showed mean pure tone averages (0.5, 1, 2, 4 kHz) of 48.6 and 47.5 dB HL in the right and left ears, respectively. Hearing was within normal limits for only 8/74 ears (11%). For the 66 ears with hearing loss, the degree was mild (12%), moderate (54%), or severe (8%). Type of hearing loss was predominantly sensorineural (77%), while three ears had mixed loss, no ears had conductive loss, and type of hearing loss was indeterminate for the remaining 12 ears. Serial audiograms available for 33 patients showed hearing loss progression of approximately 10-15 dB/decade. Our data show that hearing loss associated with AS begins in childhood and is a predominantly symmetric, sensory hearing loss that may progress to a severe degree. Absent otoacoustic emissions, intact speech discrimination, and disproportionately normal auditory brainstem responses suggest an outer hair cell site of lesion. These findings indicate that individuals with AS would benefit from sound amplification and if necessary, cochlear implantation.
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Affiliation(s)
- Spencer Lindsey
- Department of Otolaryngology-Head and Neck Surgery, Georgetown University Hospital, Washington, D.C
| | - Carmen Brewer
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Olga Stakhovskaya
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Hung Jeffrey Kim
- Department of Otolaryngology-Head and Neck Surgery, Georgetown University Hospital, Washington, D.C
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Chris Zalewski
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | - Joy Bryant
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Kelly A King
- Otolaryngology Branch, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Bethesda, Maryland
| | | | - William A Gahl
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
- NIH Undiagnosed Diseases Program, Common Fund, Office of the Director, National Institutes of Health, Bethesda, Maryland
- Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Jan D Marshall
- The Jackson Laboratory, Bar Harbor, Maine
- Alström Syndrome International, Bar Harbor, Maine
| | - Meral Gunay-Aygun
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
- Office of the Clinical Director, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
- Johns Hopkins University School of Medicine, Department of Pediatrics and McKusick-Nathans Institute of Genetic Medicine, Baltimore, Maryland
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Zhang S, Zhang Y, Yu P, Hu Y, Zhou H, Guo L, Xu X, Zhu X, Waqas M, Qi J, Zhang X, Liu Y, Chen F, Tang M, Qian X, Shi H, Gao X, Chai R. Characterization of Lgr5+ Progenitor Cell Transcriptomes after Neomycin Injury in the Neonatal Mouse Cochlea. Front Mol Neurosci 2017; 10:213. [PMID: 28725177 PMCID: PMC5496572 DOI: 10.3389/fnmol.2017.00213] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Accepted: 06/16/2017] [Indexed: 12/17/2022] Open
Abstract
Lgr5+ supporting cells (SCs) are enriched hair cell (HC) progenitors in the cochlea. Both in vitro and in vivo studies have shown that HC injury can spontaneously activate Lgr5+ progenitors to regenerate HCs in the neonatal mouse cochlea. Promoting HC regeneration requires the understanding of the mechanism of HC regeneration, and this requires knowledge of the key genes involved in HC injury-induced self-repair responses that promote the proliferation and differentiation of Lgr5+ progenitors. Here, as expected, we found that neomycin-treated Lgr5+ progenitors (NLPs) had significantly greater HC regeneration ability, and greater but not significant proliferation ability compared to untreated Lgr5+ progenitors (ULPs) in response to neomycin exposure. Next, we used RNA-seq analysis to determine the differences in the gene-expression profiles between the transcriptomes of NLPs and ULPs from the neonatal mouse cochlea. We first analyzed the genes that were enriched and differentially expressed in NLPs and ULPs and then analyzed the cell cycle genes, the transcription factors, and the signaling pathway genes that might regulate the proliferation and differentiation of Lgr5+ progenitors. We found 9 cell cycle genes, 88 transcription factors, 8 microRNAs, and 16 cell-signaling pathway genes that were significantly upregulated or downregulated after neomycin injury in NLPs. Lastly, we constructed a protein-protein interaction network to show the interaction and connections of genes that are differentially expressed in NLPs and ULPs. This study has identified the genes that might regulate the proliferation and HC regeneration of Lgr5+ progenitors after neomycin injury, and investigations into the roles and mechanisms of these genes in the cochlea should be performed in the future to identify potential therapeutic targets for HC regeneration.
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Affiliation(s)
- Shasha Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China.,Research Institute of OtolaryngologyNanjing, China.,Co-innovation Center of Neuroregeneration, Nantong UniversityNantong, China
| | - Yuan Zhang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China
| | - Pengfei Yu
- Bioinformatics Department, Admera Health LLCSouth Plainfield, NJ, United States
| | - Yao Hu
- School of Pharmacy, Institute for Stem Cell and Neural Regeneration, Nanjing Medical UniversityNanjing, China
| | - Han Zhou
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjing, China
| | - Lingna Guo
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China
| | - Xiaochen Xu
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China
| | - Xiaocheng Zhu
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjing, China
| | - Muhammad Waqas
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China.,Department of Biotechnology, Federal Urdu University of Arts, Science and TechnologyKarachi, Pakistan
| | - Jieyu Qi
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China
| | - Xiaoli Zhang
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjing, China
| | - Yan Liu
- School of Pharmacy, Institute for Stem Cell and Neural Regeneration, Nanjing Medical UniversityNanjing, China
| | - Fangyi Chen
- Department of Biomedical Engineering, Southern University of Science and TechnologyShenzhen, China
| | - Mingliang Tang
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China
| | - Xiaoyun Qian
- Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjing, China
| | - Haibo Shi
- Department of Otorhinolaryngology Head and Neck Surgery, The Sixth People's Hospital Affiliated to Shanghai Jiao Tong UniversityShanghai, China
| | - Xia Gao
- Research Institute of OtolaryngologyNanjing, China.,Jiangsu Provincial Key Medical Discipline (Laboratory), Department of Otolaryngology Head and Neck Surgery, Affiliated Drum Tower Hospital of Nanjing University Medical SchoolNanjing, China
| | - Renjie Chai
- Key Laboratory for Developmental Genes and Human Disease, Ministry of Education, Institute of Life Sciences, Southeast UniversityNanjing, China.,Research Institute of OtolaryngologyNanjing, China.,Co-innovation Center of Neuroregeneration, Nantong UniversityNantong, China
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Chen J, Geberhiwot T, Barrett TG, Paisey R, Semple RK. Refining genotype-phenotype correlation in Alström syndrome through study of primary human fibroblasts. Mol Genet Genomic Med 2017; 5:390-404. [PMID: 28717663 PMCID: PMC5511801 DOI: 10.1002/mgg3.296] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 04/11/2017] [Accepted: 04/13/2017] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Alström syndrome (AS), featuring retinal dystrophy, neuronal deafness, cardiomyopathy, metabolic syndrome, and diffuse fibrosis, is caused by biallelic mutations in the centrosomal protein ALMS1. Genotype-phenotype correlation has been suggested without assessment of ALMS1 expression. METHODS ALMS1 expression (real-time PCR and immunocytochemistry) and cilia formation (immunocytochemistry) were assessed in fibroblasts from deeply phenotyped volunteers diagnosed with AS recruited from a dedicated AS Service. Exome sequencing was used in two participants without convincing biallelic ALMS1 mutations, and BBS2 (Bardet-Biedl syndrome 2) protein expression was assessed in one patient with biallelic BBS2 mutations. Hedgehog-induced GLI1 expression and PDGFA signaling was assessed using quantitative real-time PCR, immunoblotting, or immunostaining of fixed cells after stimulation. RESULTS In 16 of the patient cell lines examined, ALMS1 protein was undetectable (14 with biallelic loss-of-function (LoF) mutations), and in two, ALMS1 staining was equivocal (one with biallelic LoF mutations). In five lines, ALMS1 expression was normal using at least one fixation method (one with biallelic LoF mutations). These differences were not accounted for by major differences in ALMS1 mRNA expression. Exome sequencing of two participants with normal ALMS1 expression identified biallelic LoF BBS2 mutations in one. No second, known ciliopathy mutation was found in the other patient, who had one LoF ALMS1 mutation. Phenotypes were milder or atypical in participants with preserved ALMS1 immunostaining, even when two with likely alternative genetic diagnoses were excluded. All cells studied developed normal cilia, ALMS1 and BBS2 mutant cells showed normal Hedgehog-induced upregulation of GLI1 expression, and PDGFA signaling was normal in ALMS1-deficient cells. CONCLUSION Milder or atypical presentations of AS should prompt genetic evaluation for alternative, clinically overlapping ciliopathies. A subgroup of patients with bona fide ALMS1 defects have milder phenotypes due to residual ALMS1 expression, which may be more important than mutation site.
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Affiliation(s)
- Jian‐Hua Chen
- Wellcome Trust‐MRC Institute of Metabolic ScienceUniversity of CambridgeCambridgeUK,The National Institute for Health Research Cambridge Biomedical Research CentreCambridgeUK
| | | | | | - Richard Paisey
- South Devon Healthcare NHS Foundation TrustTorbay HospitalTorquayUK
| | - Robert K. Semple
- Wellcome Trust‐MRC Institute of Metabolic ScienceUniversity of CambridgeCambridgeUK,The National Institute for Health Research Cambridge Biomedical Research CentreCambridgeUK
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37
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Shi W, Xie Y, He J, Zhou J, Gao Y, Wei W, Ding N, Ma H, Xian CJ, Chen K, Wang J. Microgravity induces inhibition of osteoblastic differentiation and mineralization through abrogating primary cilia. Sci Rep 2017; 7:1866. [PMID: 28500304 PMCID: PMC5431935 DOI: 10.1038/s41598-017-02049-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2016] [Accepted: 04/05/2017] [Indexed: 12/17/2022] Open
Abstract
It is well documented that microgravity in space environment leads to bone loss in astronauts. These physiological changes have also been validated by human and animal studies and modeled in cell-based analogs. However, the underlying mechanisms are elusive. In the current study, we identified a novel phenomenon that primary cilia (key sensors and functioning organelles) of rat calvarial osteoblasts (ROBs) gradually shrank and disappeared almost completely after exposure to simulated microgravity generated by a random positioning machine (RPM). Along with the abrogation of primary cilia, the differentiation, maturation and mineralization of ROBs were inhibited. We also found that the disappearance of primary cilia was prevented by treating ROBs with cytochalasin D, but not with LiCl or dynein light chain Tctex-type 1 (Dynlt1) siRNA. The repression of the differentiation, maturation and mineralization of ROBs was effectively offset by cytochalasin D treatment in microgravity conditions. Blocking ciliogenesis using intraflagellar transport protein 88 (IFT88) siRNA knockdown inhibited the ability of cytochalasin D to counteract this reduction of osteogenesis. These results indicate that the abrogation of primary cilia may be responsible for the microgravity's inhibition on osteogenesis. Reconstruction of primary cilia may become a potential strategy against bone loss induced by microgravity.
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Affiliation(s)
- Wengui Shi
- Gansu Key laboratory of Space Radiobiology, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Yanfang Xie
- Institute of Orthopaedics, Lanzhou General Hospital, Lanzhou Command of CPLA, Lanzhou, 730050, P. R. China
| | - Jinpeng He
- Gansu Key laboratory of Space Radiobiology, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
| | - Jian Zhou
- Institute of Orthopaedics, Lanzhou General Hospital, Lanzhou Command of CPLA, Lanzhou, 730050, P. R. China
| | - Yuhai Gao
- Institute of Orthopaedics, Lanzhou General Hospital, Lanzhou Command of CPLA, Lanzhou, 730050, P. R. China
| | - Wenjun Wei
- Gansu Key laboratory of Space Radiobiology, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
- University of Chinese Academy of Sciences, Beijing, 100049, P. R. China
| | - Nan Ding
- Gansu Key laboratory of Space Radiobiology, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China
| | - Huiping Ma
- Institute of Orthopaedics, Lanzhou General Hospital, Lanzhou Command of CPLA, Lanzhou, 730050, P. R. China
| | - Cory J Xian
- Sansom Institute for Health Research, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA 5001, Australia
| | - Keming Chen
- Institute of Orthopaedics, Lanzhou General Hospital, Lanzhou Command of CPLA, Lanzhou, 730050, P. R. China.
| | - Jufang Wang
- Gansu Key laboratory of Space Radiobiology, Institute of Modern Physics, Chinese Academy of Sciences, Lanzhou, 730000, P. R. China.
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Forge A, Taylor RR, Dawson SJ, Lovett M, Jagger DJ. Disruption of SorCS2 reveals differences in the regulation of stereociliary bundle formation between hair cell types in the inner ear. PLoS Genet 2017; 13:e1006692. [PMID: 28346477 PMCID: PMC5386298 DOI: 10.1371/journal.pgen.1006692] [Citation(s) in RCA: 12] [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: 11/01/2016] [Revised: 04/10/2017] [Accepted: 03/14/2017] [Indexed: 12/24/2022] Open
Abstract
Behavioural anomalies suggesting an inner ear disorder were observed in a colony of transgenic mice. Affected animals were profoundly deaf. Severe hair bundle defects were identified in all outer and inner hair cells (OHC, IHC) in the cochlea and in hair cells of vestibular macular organs, but hair cells in cristae were essentially unaffected. Evidence suggested the disorder was likely due to gene disruption by a randomly inserted transgene construct. Whole-genome sequencing identified interruption of the SorCS2 (Sortilin-related VPS-10 domain containing protein) locus. Real-time-qPCR demonstrated disrupted expression of SorCS2 RNA in cochlear tissue from affected mice and this was confirmed by SorCS2 immuno-labelling. In all affected hair cells, stereocilia were shorter than normal, but abnormalities of bundle morphology and organisation differed between hair cell types. Bundles on OHC were grossly misshapen with significantly fewer stereocilia than normal. However, stereocilia were organised in rows of increasing height. Bundles on IHC contained significantly more stereocilia than normal with some longer stereocilia towards the centre, or with minimal height differentials. In early postnatal mice, kinocilia (primary cilia) of IHC and of OHC were initially located towards the lateral edge of the hair cell surface but often became surrounded by stereocilia as bundle shape and apical surface contour changed. In macular organs the kinocilium was positioned in the centre of the cell surface throughout maturation. There was disruption of the signalling pathway controlling intrinsic hair cell apical asymmetry. LGN and Gαi3 were largely absent, and atypical Protein Kinase C (aPKC) lost its asymmetric distribution. The results suggest that SorCS2 plays a role upstream of the intrinsic polarity pathway and that there are differences between hair cell types in the deployment of the machinery that generates a precisely organised hair bundle.
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MESH Headings
- Age Factors
- Animals
- Gene Expression Regulation
- Hair Cells, Auditory, Inner/metabolism
- Hair Cells, Auditory, Inner/pathology
- Hearing Loss/genetics
- Hearing Loss/metabolism
- Hearing Loss/physiopathology
- Immunohistochemistry
- Mice, Inbred C57BL
- Mice, Knockout
- Mice, Transgenic
- Microscopy, Confocal
- Microscopy, Electron, Scanning
- Nerve Tissue Proteins/genetics
- Nerve Tissue Proteins/metabolism
- Organ of Corti/metabolism
- Organ of Corti/physiopathology
- Organ of Corti/ultrastructure
- Receptors, Cell Surface/genetics
- Receptors, Cell Surface/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Stereocilia/genetics
- Stereocilia/metabolism
- Stereocilia/pathology
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Affiliation(s)
- Andrew Forge
- UCL Ear Institute, University College London, London, United Kingdom
- * E-mail:
| | - Ruth R. Taylor
- UCL Ear Institute, University College London, London, United Kingdom
| | - Sally J. Dawson
- UCL Ear Institute, University College London, London, United Kingdom
| | - Michael Lovett
- National Heart and Lung Institute, Imperial College London, London, United Kingdom
| | - Daniel J. Jagger
- UCL Ear Institute, University College London, London, United Kingdom
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Ick Ciliary Kinase Is Essential for Planar Cell Polarity Formation in Inner Ear Hair Cells and Hearing Function. J Neurosci 2017; 37:2073-2085. [PMID: 28115485 DOI: 10.1523/jneurosci.3067-16.2017] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 01/06/2017] [Accepted: 01/11/2017] [Indexed: 11/21/2022] Open
Abstract
Cellular asymmetries play crucial roles in development and organ function. The planar cell polarity (PCP) signaling pathway is involved in the establishment of cellular asymmetry within the plane of a cell sheet. Inner ear sensory hair cells (HCs), which have several rows of staircase-like stereocilia and one kinocilium located at the vertex of the stereocilia protruding from the apical surface of each HC, exhibit a typical form of PCP. Although connections between cilia and PCP signaling in vertebrate development have been reported, their precise nature is not well understood. During inner ear development, several ciliary proteins are known to play a role in PCP formation. In the current study, we investigated a functional role for intestinal cell kinase (Ick), which regulates intraflagellar transport (IFT) at the tip of cilia, in the mouse inner ear. A lack of Ick in the developing inner ear resulted in PCP defects in the cochlea, including misorientation or misshaping of stereocilia and aberrant localization of the kinocilium and basal body in the apical and middle turns, leading to auditory dysfunction. We also observed abnormal ciliary localization of Ift88 in both HCs and supporting cells. Together, our results show that Ick ciliary kinase is essential for PCP formation in inner ear HCs, suggesting that ciliary transport regulation is important for PCP signaling.SIGNIFICANCE STATEMENT The cochlea in the inner ear is the hearing organ. Planar cell polarity (PCP) in hair cells (HCs) in the cochlea is essential for mechanotransduction and refers to the asymmetric structure consisting of stereociliary bundles and the kinocilium on the apical surface of the cell body. We reported previously that a ciliary kinase, Ick, regulates intraflagellar transport (IFT). Here, we found that loss of Ick leads to abnormal localization of the IFT component in kinocilia, PCP defects in HCs, and hearing dysfunction. Our study defines the association of ciliary transport regulation with PCP formation in HCs and hearing function.
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40
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Larrañaga-Fragoso P, Pastora N, Bravo-Ljubetic L, Peralta J, Abelairas-Gómez J. Topical carbonic anhydrase inhibitors in macular edema associated with Alström syndrome. Ophthalmic Genet 2016; 37:427-429. [PMID: 26894450 DOI: 10.3109/13816810.2015.1094493] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
BACKGROUND Alström syndrome is a rare genetic ciliopathy caused by a mutation in the ALMS1 gene. The syndrome is characterized by cone-rod dystrophy, dilated myocardiopathy, childhood obesity and sensorineural hearing loss. To date, cystoid macular edema has not been reported. METHODS A female affected by Alström syndrome developed bilateral cystoid macular edema evidenced by optical coherence tomography. A topical carbonic anhydrase inhibitor was prescribed. RESULTS Complete resolution of the cystoid macular edema was achieved, though visual acuity did not improve. CONCLUSIONS Topical carbonic anhydrase inhibitors may have a role in the treatment of macular edema in syndromic retinal dystrophies such as Alström syndrome.
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Affiliation(s)
| | - Natalia Pastora
- a Pediatric Ophthalmology Department , Hospital Universitario La Paz , Madrid , Spain
| | - Luciano Bravo-Ljubetic
- a Pediatric Ophthalmology Department , Hospital Universitario La Paz , Madrid , Spain.,b Ophthalmology Department , Hospital Clínico San Borja Arriarán , Santiago , Chile
| | - Jesús Peralta
- a Pediatric Ophthalmology Department , Hospital Universitario La Paz , Madrid , Spain
| | - José Abelairas-Gómez
- a Pediatric Ophthalmology Department , Hospital Universitario La Paz , Madrid , Spain
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41
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Cilia-Associated Genes Play Differing Roles in Aminoglycoside-Induced Hair Cell Death in Zebrafish. G3-GENES GENOMES GENETICS 2016; 6:2225-35. [PMID: 27207957 PMCID: PMC4938675 DOI: 10.1534/g3.116.030080] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Hair cells possess a single primary cilium, called the kinocilium, early in development. While the kinocilium is lost in auditory hair cells of most species it is maintained in vestibular hair cells. It has generally been believed that the primary role of the kinocilium and cilia-associated genes in hair cells is in the establishment of the polarity of actin-based stereocilia, the hair cell mechanotransduction apparatus. Through genetic screening and testing of candidate genes in zebrafish (Danio rerio) we have found that mutations in multiple cilia genes implicated in intraflagellar transport (dync2h1, wdr35, ift88, and traf3ip), and the ciliary transition zone (cc2d2a, mks1, and cep290) lead to resistance to aminoglycoside-induced hair cell death. These genes appear to have differing roles in hair cells, as mutations in intraflagellar transport genes, but not transition zone genes, lead to defects in kinocilia formation and processes dependent upon hair cell mechanotransduction activity. These mutants highlight a novel role of cilia-associated genes in hair cells, and provide powerful tools for further study.
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42
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Paisey RB, Leeson-Beevers K. Current management of Alström syndrome and recent advances in treatment. Expert Opin Orphan Drugs 2016. [DOI: 10.1080/21678707.2016.1189322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- R. B. Paisey
- Diabetes Research, Horizon Centre, Torbay Hospital, Torquay, UK
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43
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Abstract
Primary cilia are organelles that are present on many different cell types, either transiently or permanently. They play a crucial role in receiving signals from the environment and passing these signals to other parts of the cell. In that way, they are involved in diverse processes such as adipocyte differentiation and olfactory sensation. Mutations in genes coding for ciliary proteins often have pleiotropic effects and lead to clinical conditions, ciliopathies, with multiple symptoms. In this study, we reviewed observations from ciliopathies with obesity as one of the symptoms. It shows that variation in cilia-related genes is itself not a major cause of obesity in the population but may be a part of the multifactorial aetiology of this complex condition. Both common polymorphisms and rare deleterious variants may contribute to the obesity risk. Genotype-phenotype relationships have been noticed. Among the ciliary genes, obesity differs with regard to severity and age of onset, which may relate to the influence of each gene on the balance between pro- and anti-adipogenic processes. Analysis of the function and location of the proteins encoded by these ciliary genes suggests that obesity is more linked to activities at the basal area of the cilium, including initiation of the intraflagellar transport, but less to the intraflagellar transport itself. Regarding the role of cilia, three possible mechanistic processes underlying obesity are described: adipogenesis, neuronal food intake regulation and food odour perception.
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44
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May-Simera H. Evaluation of Planar-Cell-Polarity Phenotypes in Ciliopathy Mouse Mutant Cochlea. J Vis Exp 2016:53559. [PMID: 26966880 DOI: 10.3791/53559] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
In recent years, primary cilia have emerged as key regulators in development and disease by influencing numerous signaling pathways. One of the earliest signaling pathways shown to be associated with ciliary function was the non-canonical Wnt signaling pathway, also referred to as planar cell polarity (PCP) signaling. One of the best places in which to study the effects of planar cell polarity (PCP) signaling during vertebrate development is the mammalian cochlea. PCP signaling disruption in the mouse cochlea disrupts cochlear outgrowth, cellular patterning and hair cell orientation, all of which are affected by cilia dysfunction. The goal of this protocol is to describe the analysis of PCP signaling in the developing mammalian cochlea via phenotypic analysis, immunohistochemistry and scanning electron microscopy. Defects in convergence and extension are manifested as a shortening of the cochlear duct and/or changes in cellular patterning, which can be quantified following dissection from developing mouse mutants. Changes in stereociliary bundle orientation and kinocilia length or positioning can be observed and quantitated using either immunofluorescence or scanning electron microscopy (SEM). A deeper insight into the role of ciliary proteins in cellular signaling pathways and other biological phenomena is crucial for our understanding of cellular and developmental biology, as well as for the development of targeted treatment strategies.
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Affiliation(s)
- Helen May-Simera
- Cell and Matrix Biology, Institute of Zoology, Johannes Gutenberg-Universität Mainz;
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45
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Pepermans E, Petit C. The tip-link molecular complex of the auditory mechano-electrical transduction machinery. Hear Res 2015; 330:10-7. [DOI: 10.1016/j.heares.2015.05.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 04/30/2015] [Accepted: 05/08/2015] [Indexed: 12/11/2022]
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46
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Falk N, Lösl M, Schröder N, Gießl A. Specialized Cilia in Mammalian Sensory Systems. Cells 2015; 4:500-19. [PMID: 26378583 PMCID: PMC4588048 DOI: 10.3390/cells4030500] [Citation(s) in RCA: 76] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 08/04/2015] [Accepted: 09/09/2015] [Indexed: 02/01/2023] Open
Abstract
Cilia and flagella are highly conserved and important microtubule-based organelles that project from the surface of eukaryotic cells and act as antennae to sense extracellular signals. Moreover, cilia have emerged as key players in numerous physiological, developmental, and sensory processes such as hearing, olfaction, and photoreception. Genetic defects in ciliary proteins responsible for cilia formation, maintenance, or function underlie a wide array of human diseases like deafness, anosmia, and retinal degeneration in sensory systems. Impairment of more than one sensory organ results in numerous syndromic ciliary disorders like the autosomal recessive genetic diseases Bardet-Biedl and Usher syndrome. Here we describe the structure and distinct functional roles of cilia in sensory organs like the inner ear, the olfactory epithelium, and the retina of the mouse. The spectrum of ciliary function in fundamental cellular processes highlights the importance of elucidating ciliopathy-related proteins in order to find novel potential therapies.
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Affiliation(s)
- Nathalie Falk
- Department of Biology, Animal Physiology, University of Erlangen-Nuremberg, 91058 Erlangen, Germany.
| | - Marlene Lösl
- Department of Biology, Animal Physiology, University of Erlangen-Nuremberg, 91058 Erlangen, Germany.
| | - Nadja Schröder
- Department of Biology, Animal Physiology, University of Erlangen-Nuremberg, 91058 Erlangen, Germany.
| | - Andreas Gießl
- Department of Biology, Animal Physiology, University of Erlangen-Nuremberg, 91058 Erlangen, Germany.
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47
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Lu X, Sipe CW. Developmental regulation of planar cell polarity and hair-bundle morphogenesis in auditory hair cells: lessons from human and mouse genetics. WILEY INTERDISCIPLINARY REVIEWS-DEVELOPMENTAL BIOLOGY 2015; 5:85-101. [PMID: 26265594 DOI: 10.1002/wdev.202] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 06/12/2015] [Accepted: 06/29/2015] [Indexed: 12/11/2022]
Abstract
Hearing loss is the most common and costly sensory defect in humans and genetic causes underlie a significant proportion of affected individuals. In mammals, sound is detected by hair cells (HCs) housed in the cochlea of the inner ear, whose function depends on a highly specialized mechanotransduction organelle, the hair bundle. Understanding the factors that regulate the development and functional maturation of the hair bundle is crucial for understanding the pathophysiology of human deafness. Genetic analysis of deafness genes in animal models, together with complementary forward genetic screens and conditional knock-out mutations in essential genes, have provided great insights into the molecular machinery underpinning hair-bundle development and function. In this review, we highlight recent advances in our understanding of hair-bundle morphogenesis, with an emphasis on the molecular pathways governing hair-bundle polarity and orientation. We next discuss the proteins and structural elements important for hair-cell mechanotransduction as well as hair-bundle cohesion and maintenance. In addition, developmental signals thought to regulate tonotopic features of HCs are introduced. Finally, novel approaches that complement classic genetics for studying the molecular etiology of human deafness are presented. WIREs Dev Biol 2016, 5:85-101. doi: 10.1002/wdev.202 For further resources related to this article, please visit the WIREs website.
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Affiliation(s)
- Xiaowei Lu
- Department of Cell Biology, University of Virginia, Charlottesville, VA, USA
| | - Conor W Sipe
- Department of Biology, University of Virginia, Charlottesville, VA, USA
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Álvarez-Satta M, Castro-Sánchez S, Valverde D. Alström syndrome: current perspectives. APPLICATION OF CLINICAL GENETICS 2015; 8:171-9. [PMID: 26229500 PMCID: PMC4516341 DOI: 10.2147/tacg.s56612] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Alström syndrome (ALMS) is a rare genetic disorder that has been included in the ciliopathies group, in the last few years. Ciliopathies are a growing group of diseases associated with defects in ciliary structure and function. The development of more powerful genetic approaches has been replaced the strategies to follow for getting a successful molecular diagnosis for these patients, especially for those without the typical ALMS phenotype. In an effort to deepen the understanding of the pathogenesis of ALMS disease, much work has been done, in order to establish the biological implication of ALMS1 protein, which is still being elucidated. In addition to its role in ciliary function and structure maintenance, this protein has been implicated in intracellular trafficking, regulation of cilia signaling pathways, and cellular differentiation, among others. All these progresses will lead to identifying therapeutic targets, thus opening the way to future personalized therapies for human ciliopathies.
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Affiliation(s)
- María Álvarez-Satta
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
| | - Sheila Castro-Sánchez
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
| | - Diana Valverde
- Departamento de Bioquímica, Genética e Inmunología, Facultad de Biología, Universidad de Vigo, Vigo, Spain
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Nadol JB, Marshall JD, Bronson RT. Histopathology of the human inner ear in Alström's syndrome. Audiol Neurootol 2015; 20:267-72. [PMID: 26111748 DOI: 10.1159/000381935] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 03/28/2015] [Indexed: 01/26/2023] Open
Abstract
Alström's syndrome is an autosomal recessive syndromic genetic disorder caused by mutations in the ALMS1 gene. Sensorineural hearing loss occurs in greater than 85% of patients. Histopathology of the inner ear abnormalities in the human has not previously been fully described. Histopathology of the inner ear in Alström's syndrome is presented in 2 genetically confirmed cases. The predominant histopathologic correlates of the sensorineural loss were degeneration of the organ of Corti, both inner and outer hair cells, degeneration of spiral ganglion cells, and atrophy of the stria vascularis and spiral ligament.
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Affiliation(s)
- Joseph B Nadol
- Otopathology Laboratory, Department of Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Mass., USA
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Abdelhamed ZA, Natarajan S, Wheway G, Inglehearn CF, Toomes C, Johnson CA, Jagger DJ. The Meckel-Gruber syndrome protein TMEM67 controls basal body positioning and epithelial branching morphogenesis in mice via the non-canonical Wnt pathway. Dis Model Mech 2015; 8:527-41. [PMID: 26035863 PMCID: PMC4457033 DOI: 10.1242/dmm.019083] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 04/01/2015] [Indexed: 01/16/2023] Open
Abstract
Ciliopathies are a group of developmental disorders that manifest with multi-organ anomalies. Mutations in TMEM67 (MKS3) cause a range of human ciliopathies, including Meckel-Gruber and Joubert syndromes. In this study we describe multi-organ developmental abnormalities in the Tmem67tm1Dgen/H1 knockout mouse that closely resemble those seen in Wnt5a and Ror2 knockout mice. These include pulmonary hypoplasia, ventricular septal defects, shortening of the body longitudinal axis, limb abnormalities, and cochlear hair cell stereociliary bundle orientation and basal body/kinocilium positioning defects. The basal body/kinocilium complex was often uncoupled from the hair bundle, suggesting aberrant basal body migration, although planar cell polarity and apical planar asymmetry in the organ of Corti were normal. TMEM67 (meckelin) is essential for phosphorylation of the non-canonical Wnt receptor ROR2 (receptor-tyrosine-kinase-like orphan receptor 2) upon stimulation with Wnt5a-conditioned medium. ROR2 also colocalises and interacts with TMEM67 at the ciliary transition zone. Additionally, the extracellular N-terminal domain of TMEM67 preferentially binds to Wnt5a in an in vitro binding assay. Cultured lungs of Tmem67 mutant mice failed to respond to stimulation of epithelial branching morphogenesis by Wnt5a. Wnt5a also inhibited both the Shh and canonical Wnt/β-catenin signalling pathways in wild-type embryonic lung. Pulmonary hypoplasia phenotypes, including loss of correct epithelial branching morphogenesis and cell polarity, were rescued by stimulating the non-canonical Wnt pathway downstream of the Wnt5a-TMEM67-ROR2 axis by activating RhoA. We propose that TMEM67 is a receptor that has a main role in non-canonical Wnt signalling, mediated by Wnt5a and ROR2, and normally represses Shh signalling. Downstream therapeutic targeting of the Wnt5a-TMEM67-ROR2 axis might, therefore, reduce or prevent pulmonary hypoplasia in ciliopathies and other congenital conditions. Highlighted Article: TMEM67 is a receptor of non-canonical Wnt signalling, implicating the Wnt5a-TMEM67-ROR2 axis during developmental signalling and disruption in ciliopathy disease state.
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Affiliation(s)
- Zakia A Abdelhamed
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK Department of Anatomy and Embryology, Faculty of Medicine, Al-Azhar University, Cairo 11844, Egypt
| | - Subaashini Natarajan
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK
| | - Gabrielle Wheway
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK
| | - Christopher F Inglehearn
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK
| | - Carmel Toomes
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK
| | - Colin A Johnson
- Ciliopathy Research Group, Section of Ophthalmology and Neurosciences, Leeds Institute of Molecular Medicine, University of Leeds, Leeds LS9 7TF, UK
| | - Daniel J Jagger
- UCL Ear Institute, University College London, 332 Gray's Inn Road, London WC1X 8EE, UK
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