1
|
Hale AT, Boudreau H, Devulapalli R, Duy PQ, Atchley TJ, Dewan MC, Goolam M, Fieggen G, Spader HL, Smith AA, Blount JP, Johnston JM, Rocque BG, Rozzelle CJ, Chong Z, Strahle JM, Schiff SJ, Kahle KT. The genetic basis of hydrocephalus: genes, pathways, mechanisms, and global impact. Fluids Barriers CNS 2024; 21:24. [PMID: 38439105 PMCID: PMC10913327 DOI: 10.1186/s12987-024-00513-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Accepted: 01/25/2024] [Indexed: 03/06/2024] Open
Abstract
Hydrocephalus (HC) is a heterogenous disease characterized by alterations in cerebrospinal fluid (CSF) dynamics that may cause increased intracranial pressure. HC is a component of a wide array of genetic syndromes as well as a secondary consequence of brain injury (intraventricular hemorrhage (IVH), infection, etc.) that can present across the age spectrum, highlighting the phenotypic heterogeneity of the disease. Surgical treatments include ventricular shunting and endoscopic third ventriculostomy with or without choroid plexus cauterization, both of which are prone to failure, and no effective pharmacologic treatments for HC have been developed. Thus, there is an urgent need to understand the genetic architecture and molecular pathogenesis of HC. Without this knowledge, the development of preventive, diagnostic, and therapeutic measures is impeded. However, the genetics of HC is extraordinarily complex, based on studies of varying size, scope, and rigor. This review serves to provide a comprehensive overview of genes, pathways, mechanisms, and global impact of genetics contributing to all etiologies of HC in humans.
Collapse
Affiliation(s)
- Andrew T Hale
- Department of Neurosurgery, University of Alabama at Birmingham, FOT Suite 1060, 1720 2ndAve, Birmingham, AL, 35294, UK.
| | - Hunter Boudreau
- Department of Neurosurgery, University of Alabama at Birmingham, FOT Suite 1060, 1720 2ndAve, Birmingham, AL, 35294, UK
| | - Rishi Devulapalli
- Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL, UK
| | - Phan Q Duy
- Department of Neurosurgery, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Travis J Atchley
- Department of Neurosurgery, University of Alabama at Birmingham, FOT Suite 1060, 1720 2ndAve, Birmingham, AL, 35294, UK
| | - Michael C Dewan
- Division of Pediatric Neurosurgery, Monroe Carell Jr. Children's Hospital, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Mubeen Goolam
- Neuroscience Institute, University of Cape Town, Cape Town, South Africa
| | - Graham Fieggen
- Neuroscience Institute, University of Cape Town, Cape Town, South Africa
- Division of Pediatric Neurosurgery, Red Cross War Memorial Children's Hospital, University of Cape Town, Cape Town, South Africa
| | - Heather L Spader
- Department of Neurosurgery, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Anastasia A Smith
- Division of Pediatric Neurosurgery, Children's of Alabama, University of Alabama at Birmingham, Birmingham, AL, UK
| | - Jeffrey P Blount
- Division of Pediatric Neurosurgery, Children's of Alabama, University of Alabama at Birmingham, Birmingham, AL, UK
| | - James M Johnston
- Division of Pediatric Neurosurgery, Children's of Alabama, University of Alabama at Birmingham, Birmingham, AL, UK
| | - Brandon G Rocque
- Division of Pediatric Neurosurgery, Children's of Alabama, University of Alabama at Birmingham, Birmingham, AL, UK
| | - Curtis J Rozzelle
- Division of Pediatric Neurosurgery, Children's of Alabama, University of Alabama at Birmingham, Birmingham, AL, UK
| | - Zechen Chong
- Heflin Center for Genomics, University of Alabama at Birmingham, Birmingham, AL, UK
| | - Jennifer M Strahle
- Division of Pediatric Neurosurgery, St. Louis Children's Hospital, Washington University in St. Louis, St. Louis, MO, USA
| | - Steven J Schiff
- Department of Neurosurgery, Yale University School of Medicine, New Haven, CT, USA
| | - Kristopher T Kahle
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| |
Collapse
|
2
|
Sun K, Liu L, Jiang X, Wang H, Wang L, Yang Y, Liu W, Zhang L, Zhao X, Zhu X. The endoplasmic reticulum membrane protein complex subunit Emc6 is essential for rhodopsin localization and photoreceptor cell survival. Genes Dis 2024; 11:1035-1049. [PMID: 37692493 PMCID: PMC10492031 DOI: 10.1016/j.gendis.2023.03.033] [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: 09/21/2022] [Revised: 02/17/2023] [Accepted: 03/29/2023] [Indexed: 09/12/2023] Open
Abstract
The endoplasmic reticulum (ER) membrane protein complex (EMC) is responsible for monitoring the biogenesis and synthetic quality of membrane proteins with tail-anchored or multiple transmembrane domains. The EMC subunit EMC6 is one of the core members of EMC and forms an enclosed hydrophilic vestibule in cooperation with EMC3. Despite studies demonstrating that deletion of EMC3 led to rhodopsin mislocalization in rod photoreceptors of mice, the precise mechanism leading to the failure of rhodopsin trafficking remains unclear. Here, we generated the first rod photoreceptor-specific knockout of Emc6 (RKO) and cone photoreceptor-specific knockout of Emc6 (CKO) mouse models. Deficiency of Emc6 in rod photoreceptors led to progressive shortening of outer segments (OS), impaired visual function, mislocalization and reduced expression of rhodopsin, and increased gliosis in rod photoreceptors. In addition, CKO mice displayed the progressive death of cone photoreceptors and abnormal localization of cone opsin protein. Subsequently, proteomics analysis of the RKO mouse retina illustrated that several cilium-related proteins, particularly anoctamin-2 (ANO2) and transmembrane protein 67 (TMEM67), were significantly down-regulated prior to OS degeneration. Detrimental rod photoreceptor cilia and mislocalized membrane disc proteins were evident in RKO mice. Our data revealed that in addition to monitoring the synthesis of rhodopsin-dominated membrane disc proteins, EMC6 also impacted rod photoreceptors' ciliogenesis by regulating the synthesis of membrane proteins associated with cilia, contributing to the mislocalization of membrane disc proteins.
Collapse
Affiliation(s)
- Kuanxiang Sun
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Key Laboratory of Tibetan Medicine Research, Chinese Academy of Sciences and Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Xining, Qinghai 810008, China
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China
| | - Lu Liu
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Xiaoyan Jiang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Heting Wang
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Lin Wang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Yeming Yang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Wenjing Liu
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Lin Zhang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Xiaohui Zhao
- Key Laboratory of Tibetan Medicine Research, Chinese Academy of Sciences and Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Xining, Qinghai 810008, China
| | - Xianjun Zhu
- Health Management Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Key Laboratory of Tibetan Medicine Research, Chinese Academy of Sciences and Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Xining, Qinghai 810008, China
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study and Department of Laboratory Medicine, Center for Medical Genetics, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072, China
- Department of Ophthalmology, The First People's Hospital of Shangqiu, Shangqiu, Henan 476000, China
| |
Collapse
|
3
|
Kalot R, Sentell Z, Kitzler TM, Torban E. Primary cilia and actin regulatory pathways in renal ciliopathies. FRONTIERS IN NEPHROLOGY 2024; 3:1331847. [PMID: 38292052 PMCID: PMC10824913 DOI: 10.3389/fneph.2023.1331847] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 12/20/2023] [Indexed: 02/01/2024]
Abstract
Ciliopathies are a group of rare genetic disorders caused by defects to the structure or function of the primary cilium. They often affect multiple organs, leading to brain malformations, congenital heart defects, and anomalies of the retina or skeletal system. Kidney abnormalities are among the most frequent ciliopathic phenotypes manifesting as smaller, dysplastic, and cystic kidneys that are often accompanied by renal fibrosis. Many renal ciliopathies cause chronic kidney disease and often progress to end-stage renal disease, necessitating replacing therapies. There are more than 35 known ciliopathies; each is a rare hereditary condition, yet collectively they account for a significant proportion of chronic kidney disease worldwide. The primary cilium is a tiny microtubule-based organelle at the apex of almost all vertebrate cells. It serves as a "cellular antenna" surveying environment outside the cell and transducing this information inside the cell to trigger multiple signaling responses crucial for tissue morphogenesis and homeostasis. Hundreds of proteins and unique cellular mechanisms are involved in cilia formation. Recent evidence suggests that actin remodeling and regulation at the base of the primary cilium strongly impacts ciliogenesis. In this review, we provide an overview of the structure and function of the primary cilium, focusing on the role of actin cytoskeleton and its regulators in ciliogenesis. We then describe the key clinical, genetic, and molecular aspects of renal ciliopathies. We highlight what is known about actin regulation in the pathogenesis of these diseases with the aim to consider these recent molecular findings as potential therapeutic targets for renal ciliopathies.
Collapse
Affiliation(s)
- Rita Kalot
- Department of Medicine and Department of Physiology, McGill University, Montreal, QC, Canada
- The Research Institute of the McGill University Health Center, Montreal, QC, Canada
| | - Zachary Sentell
- Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Thomas M. Kitzler
- Department of Human Genetics, McGill University, Montreal, QC, Canada
- McGill University Health Center, Montreal, QC, Canada
| | - Elena Torban
- Department of Medicine and Department of Physiology, McGill University, Montreal, QC, Canada
- The Research Institute of the McGill University Health Center, Montreal, QC, Canada
| |
Collapse
|
4
|
Wang S, Wang X, Pan C, Liu Y, Lei M, Guo X, Chen Q, Yang X, Ouyang C, Ren Z. Functions of actin-binding proteins in cilia structure remodeling and signaling. Biol Cell 2023; 115:e202300026. [PMID: 37478133 DOI: 10.1111/boc.202300026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 07/04/2023] [Accepted: 07/11/2023] [Indexed: 07/23/2023]
Abstract
Cilia are microtubule-based organelles found on the surfaces of many types of cells, including cardiac fibroblasts, vascular endothelial cells, human retinal pigmented epithelial-1 (RPE-1) cells, and alveolar epithelial cells. These organelles can be classified as immotile cilia, referred to as primary cilia in mammalian cells, and motile cilia. Primary cilia are cellular sensors that detect extracellular signals; this is a critical function associated with ciliopathies, which are characterized by the typical clinical features of developmental disorders. Cilia are extensively studied organelles of the microtubule cytoskeleton. However, the ciliary actin cytoskeleton has rarely been studied. Clear evidence has shown that highly regulated actin cytoskeleton dynamics contribute to normal ciliary function. Actin-binding proteins (ABPs) play vital roles in filamentous actin (F-actin) morphology. Here, we discuss recent progress in understanding the roles of ABPs in ciliary structural remodeling and further downstream ciliary signaling with a focus on the molecular mechanisms underlying actin cytoskeleton-related ciliopathies.
Collapse
Affiliation(s)
- Siqi Wang
- Hubei Key Laboratory of Diabetes and Angiopathy, Medicine Research Institute, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Xin Wang
- School of Mathematics and Statistics, Hubei University of Science and Technology, Xianning, China
| | - Congbin Pan
- Hubei Key Laboratory of Diabetes and Angiopathy, Medicine Research Institute, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Ying Liu
- College of Life Sciences, Shandong Provincial Key Laboratory of Animal Resistance Biology, Shandong Normal University, Jinan, China
| | - Min Lei
- Hubei Key Laboratory of Diabetes and Angiopathy, Medicine Research Institute, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Xiying Guo
- Hubei Key Laboratory of Diabetes and Angiopathy, Medicine Research Institute, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Qingjie Chen
- Hubei Key Laboratory of Diabetes and Angiopathy, Medicine Research Institute, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Xiaosong Yang
- Hubei Key Laboratory of Diabetes and Angiopathy, Medicine Research Institute, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Changhan Ouyang
- School of Pharmacy, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| | - Zhanhong Ren
- Hubei Key Laboratory of Diabetes and Angiopathy, Medicine Research Institute, Xianning Medical College, Hubei University of Science and Technology, Xianning, China
| |
Collapse
|
5
|
Serpieri V, Mortarini G, Loucks H, Biagini T, Micalizzi A, Palmieri I, Dempsey JC, D'Abrusco F, Mazzotta C, Battini R, Bertini ES, Boltshauser E, Borgatti R, Brockmann K, D'Arrigo S, Nardocci N, Fischetto R, Agolini E, Novelli A, Romano A, Romaniello R, Stanzial F, Signorini S, Strisciuglio P, Gana S, Mazza T, Doherty D, Valente EM. Recurrent, founder and hypomorphic variants contribute to the genetic landscape of Joubert syndrome. J Med Genet 2023; 60:885-893. [PMID: 36788019 PMCID: PMC10447400 DOI: 10.1136/jmg-2022-108725] [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: 05/24/2022] [Accepted: 01/08/2023] [Indexed: 02/16/2023]
Abstract
BACKGROUND Joubert syndrome (JS) is a neurodevelopmental ciliopathy characterised by a distinctive mid-hindbrain malformation, the 'molar tooth sign'. Over 40 JS-associated genes are known, accounting for two-thirds of cases. METHODS While most variants are novel or extremely rare, we report on 11 recurring variants in seven genes, including three known 'founder variants' in the Ashkenazi Jewish, Hutterite and Finnish populations. We evaluated variant frequencies in ~550 European patients with JS and compared them with controls (>15 000 Italian plus gnomAD), and with an independent cohort of ~600 JS probands from the USA. RESULTS All variants were markedly enriched in the European JS cohort compared with controls. When comparing allele frequencies in the two JS cohorts, the Ashkenazim founder variant (TMEM216 c.218G>T) was significantly enriched in American compared with European patients with JS, while MKS1 c.1476T>G was about 10 times more frequent among European JS. Frequencies of other variants were comparable in the two cohorts. Genotyping of several markers identified four novel European founder haplotypes.Two recurrent variants (MKS1 c.1476T>G and KIAA0586 c.428delG), have been detected in homozygosity in unaffected individuals, suggesting they could act as hypomorphic variants. However, while fibroblasts from a MKS1 c.1476T>G healthy homozygote showed impaired ability to form primary cilia and mildly reduced ciliary length, ciliary parameters were normal in cells from a KIAA0586 c.428delG healthy homozygote. CONCLUSION This study contributes to understand the complex genetic landscape of JS, explain its variable prevalence in distinct geographical areas and characterise two recurrent hypomorphic variants.
Collapse
Affiliation(s)
| | - Giulia Mortarini
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | - Hailey Loucks
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Tommaso Biagini
- Bioinformatics Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, S. Giovanni Rotondo, Foggia, Italy
| | - Alessia Micalizzi
- Laboratory of Medical Genetics, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Ilaria Palmieri
- Neurogenetics Research Centre, IRCCS Mondino Foundation, Pavia, Italy
| | - Jennifer C Dempsey
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Fulvio D'Abrusco
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| | | | - Roberta Battini
- Department of Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy
- Department of Clinical and Experimental Medicine, University of Pisa, Pisa, Italy
| | - Enrico Silvio Bertini
- Unit of Neuromuscular and Neurodegenerative Disorders, IRCCS Ospedale Pediatrico Bambino Gesù, Rome, Italy
| | - Eugen Boltshauser
- Departement of Pediatric Neurology, University Children's Hospital Zürich, Zurich, Switzerland
| | - Renato Borgatti
- Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
- Child Neurology and Psychiatry Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - Knut Brockmann
- Interdisciplinary Pediatric Centre for Children with Developmental Disabilities and Severe Chronic Disorders, University Medical Centre, Georg August University, Göttingen, Germany
| | - Stefano D'Arrigo
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico "C Besta", Milan, Italy
| | - Nardo Nardocci
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico "C Besta", Milan, Italy
| | - Rita Fischetto
- Clinical Genetics Unit, Department of Pediatric Medicine, Giovanni XXIII Children's Hospital, Bari, Italy
| | - Emanuele Agolini
- Laboratory of Medical Genetics, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Antonio Novelli
- Laboratory of Medical Genetics, IRCCS Bambino Gesù Children's Hospital, Rome, Italy
| | - Alfonso Romano
- Section of Pediatrics, Department of Medical Translational Sciences, University of Naples Federico II, Naples, Italy
| | - Romina Romaniello
- Child Neurology and Psychiatry Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - Franco Stanzial
- Genetic Counseling Service, Department of Pediatrics, Regional Hospital of Bozen, Bozen, Italy
| | - Sabrina Signorini
- Child Neurology and Psychiatry Unit, IRCCS Mondino Foundation, Pavia, Italy
| | - Pietro Strisciuglio
- Section of Pediatrics, Department of Medical Translational Sciences, University of Naples Federico II, Naples, Italy
| | - Simone Gana
- Neurogenetics Research Centre, IRCCS Mondino Foundation, Pavia, Italy
| | - Tommaso Mazza
- Bioinformatics Unit, Fondazione IRCCS Casa Sollievo della Sofferenza, S. Giovanni Rotondo, Foggia, Italy
| | - Dan Doherty
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
| | - Enza Maria Valente
- Neurogenetics Research Centre, IRCCS Mondino Foundation, Pavia, Italy
- Department of Molecular Medicine, University of Pavia, Pavia, Italy
| |
Collapse
|
6
|
Sambharia M, Freese ME, Donato F, Bathla G, Abukhiran IMM, Dantuma MI, Mansilla MA, Thomas CP. Suspected Autosomal Recessive Polycystic Kidney Disease but Cerebellar Vermis Hypoplasia, Oligophrenia Ataxia, Coloboma, and Hepatic Fibrosis (COACH) Syndrome in Retrospect, A Delayed Diagnosis Aided by Genotyping and Reverse Phenotyping: A Case Report and A Review of the Literature. Nephron Clin Pract 2023; 148:264-272. [PMID: 36617405 DOI: 10.1159/000527991] [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] [Received: 05/05/2022] [Accepted: 10/20/2022] [Indexed: 01/07/2023] Open
Abstract
The clinical features of cerebellar vermis hypoplasia, oligophrenia, ataxia, coloboma, and hepatic fibrosis (COACH) characterize the rare autosomal recessive multisystem disorder called COACH syndrome. COACH syndrome belongs to the spectrum of Joubert syndrome and related disorders (JSRDs) and liver involvement distinguishes COACH syndrome from the rest of the JSRD spectrum. Developmental delay and oculomotor apraxia occur early but with time, these can improve and may not be readily apparent or no longer need active medical management. Congenital hepatic fibrosis and renal disease, on the other hand, may develop late, and the temporal incongruity in organ system involvement may delay the recognition of COACH syndrome. We present a case of a young adult presenting late to a Renal Genetics Clinic for evaluation of renal cystic disease with congenital hepatic fibrosis, clinically suspected to have autosomal recessive polycystic kidney disease. Following genetic testing, a reevaluation of his medical records from infancy, together with reverse phenotyping and genetic phasing, led to a diagnosis of COACH syndrome.
Collapse
Affiliation(s)
- Meenakshi Sambharia
- Division of Nephrology, Department of Internal Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Margaret E Freese
- Division of Nephrology, Department of Internal Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Francisco Donato
- Department of Radiology, University of Iowa, Iowa City, Iowa, USA
| | - Girish Bathla
- Department of Radiology, University of Iowa, Iowa City, Iowa, USA
| | | | - Maisie I Dantuma
- The Iowa Institute of Human Genetics, University of Iowa, Iowa City, Iowa, USA
| | - M Adela Mansilla
- The Iowa Institute of Human Genetics, University of Iowa, Iowa City, Iowa, USA
| | - Christie P Thomas
- Division of Nephrology, Department of Internal Medicine, University of Iowa, Iowa City, Iowa, USA
- The Iowa Institute of Human Genetics, University of Iowa, Iowa City, Iowa, USA
- Department of Pediatrics, College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Veterans Affairs Medical Center, Iowa City, Iowa, USA
| |
Collapse
|
7
|
Amorini M, Iapadre G, Mancuso A, Ceravolo I, Farello G, Scardamaglia A, Gramaglia S, Ceravolo A, Salpietro A, Cuppari C. An Overview of Genes Involved in the Pure Joubert Syndrome and in Joubert Syndrome-Related Disorders (JSRD). JOURNAL OF PEDIATRIC NEUROLOGY 2023. [DOI: 10.1055/s-0042-1760242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
AbstractJoubert syndrome (JS) is a rare autosomal recessive disease characterized by a peculiar brain malformation, hypotonia, ataxia, developmental delay, abnormal eye movements, and neonatal breathing abnormalities. This picture is often associated with variable multiorgan involvement, mainly of the retina, kidneys and liver, defining a group of conditions termed syndrome and Joubert syndrome-related disorders (JSRD). Currently, more than 30 causative genes have been identified, involved in the development and stability of the primary cilium. Correlations genotype–phenotype are emerging between clinical presentations and mutations in JSRD genes, with implications in terms of molecular diagnosis, prenatal diagnosis, follow-up, and management of mutated patients.
Collapse
Affiliation(s)
- Maria Amorini
- Unit of Pediatric Emergency, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” University of Messina, Messina, Italy
| | - Giulia Iapadre
- Department of Pediatrics, University of L'Aquila, L'Aquila, Italy
| | - Alessio Mancuso
- Unit of Pediatric Emergency, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” University of Messina, Messina, Italy
| | - Ida Ceravolo
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Giovanni Farello
- Department of Life, Health and Environmental Sciences, Pediatric Clinic, Coppito (AQ), Italy
| | - Annarita Scardamaglia
- Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Simone Gramaglia
- Unit of Pediatric Emergency, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” University of Messina, Messina, Italy
| | | | | | - Caterina Cuppari
- Unit of Pediatric Emergency, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” University of Messina, Messina, Italy
| |
Collapse
|
8
|
Valentini G, Saia M, Farello G, Salpietro V, Mancuso A, Ceravolo I, Colucci PV, Torre M, Iapadre G, Rosa GD, Cucinotta F. Meckel Syndrome: A Clinical and Molecular Overview. JOURNAL OF PEDIATRIC NEUROLOGY 2022. [DOI: 10.1055/s-0042-1759531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
AbstractMeckel syndrome (MKS) is a lethal, autosomal recessive, congenital syndrome caused by mutations in genes that encode proteins structurally or functionally related to the primary cilium. MKS is a malformative syndrome, most commonly characterized by occipital meningoencephalocele, polycystic kidney disease, liver fibrosis, and post- and (occasionally) preaxial polydactyly. To date, more than 10 genes are known to constitute the molecular background of MKS, displaying genetic heterogeneity. Individuals with MKS may resemble some phenotypic features of Joubert syndrome and related disorders, thus making diagnostic setting quite challenging. Here, we systematically reviewed the main clinical and genetic characteristics of MKS and its role among ciliopathies.
Collapse
Affiliation(s)
- Giulia Valentini
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “G. Barresi,” University Hospital of Messina, Messina, Italy
| | - Maria Saia
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “G. Barresi,” University Hospital of Messina, Messina, Italy
| | - Giovanni Farello
- Pediatric Clinic–Department of Life, Health and Environmental Sciences–Piazzale Salvatore Tommasi 1, Coppito (AQ), Italy
| | | | - Alessio Mancuso
- Unit of Pediatric Emergency, Department of Human Pathology of the Adult and Developmental Age “Gaetano Barresi,” University of Messina, Messina, Italy
| | - Ida Ceravolo
- Department of Clinical and Experimental Medicine, University of Messina, Via C. Valeria, Messina, Italy
| | - Pia V. Colucci
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “G. Barresi,” University Hospital of Messina, Messina, Italy
| | - Manuela Torre
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “G. Barresi,” University Hospital of Messina, Messina, Italy
| | - Giulia Iapadre
- Department of Pediatrics, University of L'Aquila, L'Aquila, Italy
| | - Gabriella Di Rosa
- Unit of Child Neurology and Psychiatry, Department of Human Pathology of the Adult and Developmental Age “G. Barresi,” University Hospital of Messina, Messina, Italy
| | | |
Collapse
|
9
|
Yinsheng Z, Miyoshi K, Qin Y, Fujiwara Y, Yoshimura T, Katayama T. TMEM67 is required for the gating function of the transition zone that controls entry of membrane-associated proteins ARL13B and INPP5E into primary cilia. Biochem Biophys Res Commun 2022; 636:162-169. [DOI: 10.1016/j.bbrc.2022.10.078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Accepted: 10/23/2022] [Indexed: 11/26/2022]
|
10
|
Qiu YL, Wang L, Huang M, Lian M, Wang F, Gong Y, Ma X, Hao CZ, Zhang J, Li ZD, Xing QH, Cao M, Wang JS. Association of novel TMEM67 variants with mild phenotypes of high gamma-glutamyl transpeptidase cholestasis and congenital hepatic fibrosis. J Cell Physiol 2022; 237:2713-2723. [PMID: 35621037 DOI: 10.1002/jcp.30788] [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: 11/16/2021] [Revised: 05/11/2022] [Accepted: 05/13/2022] [Indexed: 11/11/2022]
Abstract
TMEM67 (mecklin or MKS3) locates in the transition zone of cilia. Dysfunction of TMEM67 disrupts cilia-related signaling and leads to developmental defects of multiple organs in humans. Typical autosomal recessive TMEM67 defects cause partial overlapping phenotypes, including abnormalities in the brain, eyes, liver, kidneys, bones, and so forth. However, emerging reports of isolated nephronophthisis suggest the possibility of a broader phenotype spectrum. In this study, we analyzed the genetic data of cholestasis patients with no obvious extrahepatic involvement but with an unexplained high level of gamma-glutamyl transpeptidase (GGT). We identified five Han Chinese patients from three unrelated families with biallelic nonnull low-frequency TMEM67 variants. All variants were predicted pathogenic in silico, of which p. Arg820Ile and p. Leu144del were previously unreported. In vitro studies revealed that the protein levels of the TMEM67 variants were significantly decreased; however, their interaction with MKS1 remained unaffected. All the patients, aged 7-39 years old, had silently progressive cholestasis with elevated GGT but had normal bilirubin levels. Histological studies of liver biopsy of patients 1, 3, and 5 showed the presence of congenital hepatic fibrosis. We conclude that variants in TMEM67 are associated with a mild phenotype of unexplained, persistent, anicteric, and high GGT cholestasis without typical symptoms of TMEM67 defects; this possibility should be considered by physicians in gastroenterology and hepatology.
Collapse
Affiliation(s)
- Yi-Ling Qiu
- The Center for Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Li Wang
- The Center for Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Min Huang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Min Lian
- Division of Gastroenterology and Hepatology, Shanghai Institute of Digestive Disease, Shanghai Jiao Tong University School of Medicine Affiliated Renji Hospital, Shanghai, China
| | - Fengbin Wang
- Department of Biochemistry and Molecular Genetics, University of Virginia School of Medicine, Charlottesville, Virginia, USA
| | - Ying Gong
- Department of Radiology, Children's Hospital of Fudan University, Shanghai, China
| | - Xiong Ma
- Division of Gastroenterology and Hepatology, Shanghai Institute of Digestive Disease, Shanghai Jiao Tong University School of Medicine Affiliated Renji Hospital, Shanghai, China
| | - Chen-Zhi Hao
- The Center for Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Jing Zhang
- The Center for Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Zhong-Die Li
- The Center for Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| | - Qing-He Xing
- Institutes of Biomedical Sciences of Fudan University, Shanghai, China
| | - Muqing Cao
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jian-She Wang
- The Center for Liver Diseases, Children's Hospital of Fudan University, Shanghai, China
| |
Collapse
|
11
|
Lange KI, Best S, Tsiropoulou S, Berry I, Johnson CA, Blacque OE. Interpreting ciliopathy-associated missense variants of uncertain significance (VUS) in Caenorhabditis elegans. Hum Mol Genet 2022; 31:1574-1587. [PMID: 34964473 PMCID: PMC9122650 DOI: 10.1093/hmg/ddab344] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 11/16/2021] [Accepted: 11/17/2021] [Indexed: 12/26/2022] Open
Abstract
Better methods are required to interpret the pathogenicity of disease-associated variants of uncertain significance (VUS), which cannot be actioned clinically. In this study, we explore the use of an animal model (Caenorhabditis elegans) for in vivo interpretation of missense VUS alleles of TMEM67, a cilia gene associated with ciliopathies. CRISPR/Cas9 gene editing was used to generate homozygous knock-in C. elegans worm strains carrying TMEM67 patient variants engineered into the orthologous gene (mks-3). Quantitative phenotypic assays of sensory cilia structure and function (neuronal dye filling, roaming and chemotaxis assays) measured how the variants impacted mks-3 gene function. Effects of the variants on mks-3 function were further investigated by looking at MKS-3::GFP localization and cilia ultrastructure. The quantitative assays in C. elegans accurately distinguished between known benign (Asp359Glu, Thr360Ala) and known pathogenic (Glu361Ter, Gln376Pro) variants. Analysis of eight missense VUS generated evidence that three are benign (Cys173Arg, Thr176Ile and Gly979Arg) and five are pathogenic (Cys170Tyr, His782Arg, Gly786Glu, His790Arg and Ser961Tyr). Results from worms were validated by a genetic complementation assay in a human TMEM67 knock-out hTERT-RPE1 cell line that tests a TMEM67 signalling function. We conclude that efficient genome editing and quantitative functional assays in C. elegans make it a tractable in vivo animal model for rapid, cost-effective interpretation of ciliopathy-associated missense VUS alleles.
Collapse
Affiliation(s)
- Karen I Lange
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Sunayna Best
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, West Yorkshire, UK
| | - Sofia Tsiropoulou
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| | - Ian Berry
- Bristol Genetics Laboratory, Pathology Sciences, Southmead Hospital, Bristol BS10 5NB, UK
| | - Colin A Johnson
- Division of Molecular Medicine, Leeds Institute of Medical Research, University of Leeds, Leeds, West Yorkshire, UK
| | - Oliver E Blacque
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield, Dublin 4, Ireland
| |
Collapse
|
12
|
Abstract
Primary cilia play a key role in the ability of cells to respond to extracellular stimuli, such as signaling molecules and environmental cues. These sensory organelles are crucial to the development of many organ systems, and defects in primary ciliogenesis lead to multisystemic genetic disorders, known as ciliopathies. Here, we review recent advances in the understanding of several key aspects of the regulation of ciliogenesis. Primary ciliogenesis is thought to take different pathways depending on cell type, and some recent studies shed new light on the cell-type-specific mechanisms regulating ciliogenesis at the apical surface in polarized epithelial cells, which are particularly relevant for many ciliopathies. Furthermore, recent findings have demonstrated the importance of actin cytoskeleton dynamics in positively and negatively regulating multiple stages of ciliogenesis, including the vesicular trafficking of ciliary components and the positioning and docking of the basal body. Finally, studies on the formation of motile cilia in multiciliated epithelial cells have revealed requirements for actin remodeling in this process too, as well as showing evidence of an additional alternative ciliogenesis pathway.
Collapse
Affiliation(s)
- Huxley K Hoffman
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Rytis Prekeris
- Department of Cell and Developmental Biology, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USA
| |
Collapse
|
13
|
Peng M, Han S, Sun J, He X, Lv Y, Yang L. Evaluation of novel compound variants of CEP290 in prenatally suspected case of Meckel syndrome through whole exome sequencing. Mol Genet Genomic Med 2022; 10:e1935. [PMID: 35352487 PMCID: PMC9034663 DOI: 10.1002/mgg3.1935] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Revised: 02/16/2022] [Accepted: 03/17/2022] [Indexed: 11/29/2022] Open
Abstract
Background Meckel syndrome (MKS) is a fatal disease characterized by multisystem fibrosis during the prenatal or perinatal period. It has an autosomal recessive genetic pattern and is characterized by meningo occipital encephalocele, polycystic kidney dysplasia, polydactyly, and hepatobiliary ductal plate malformation. Germline variations in CEP290 have been shown to cause MKS4. Methods In this study, a 23‐year‐old Chinese woman who was 18 weeks pregnant was examined. The pregnancy was terminated due to occipital meningocele and enlarged cystic dysplastic kidney revealed by ultrasonography. In addition, the patient had a history of adverse pregnancy whereby the fetus presented with double kidney enlargement. Karyotype analysis and chromosomal microarray examination (CMA) were carried out using amniotic fluid samples. Whole exome sequencing (WES) was performed using tissue specimens of the aborted fetus. Results Karyotype and CMA analyses showed normal results. However, compound heterozygous mutations of CEP290 c.3175dup and CEP290 c.1201dup were detected through WES. CEP290 c.1201dup is a novel heterozygous mutation of CEP290 that has not been reported previously. Conclusions The findings of this study provide information on the correlation between MKS phenotype and genotype in CEP290. In addition, these findings indicate that WES is an effective method for detecting genetic causes of multiple structural defects especially those showing normal karyotype and CMA results.
Collapse
Affiliation(s)
- Meilian Peng
- Center for Reproductive Medicine, Department of Obstetrics, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, China
| | - Shuai Han
- Center for Reproductive Medicine, Department of Obstetrics, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, China
| | - Juan Sun
- Center for Reproductive Medicine, Department of Ultrasound Medicine, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, China
| | - Xiaodong He
- Cancer Center, Department of Radiology, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, China
| | - Yaer Lv
- Center for Reproductive Medicine, Department of Ultrasound Medicine, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, China
| | - Liwei Yang
- Center for Reproductive Medicine, Department of Obstetrics, Zhejiang Provincial People's Hospital (Affiliated People's Hospital, Hangzhou Medical College), Hangzhou, China
| |
Collapse
|
14
|
Szymanska K, Boldt K, Logan CV, Adams M, Robinson PA, Ueffing M, Zeqiraj E, Wheway G, Johnson CA. Regulation of canonical Wnt signalling by the ciliopathy protein MKS1 and the E2 ubiquitin-conjugating enzyme UBE2E1. eLife 2022; 11:57593. [PMID: 35170427 PMCID: PMC8880992 DOI: 10.7554/elife.57593] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2020] [Accepted: 02/10/2022] [Indexed: 11/24/2022] Open
Abstract
Primary ciliary defects cause a group of developmental conditions known as ciliopathies. Here, we provide mechanistic insight into ciliary ubiquitin processing in cells and for mouse model lacking the ciliary protein Mks1. In vivo loss of Mks1 sensitises cells to proteasomal disruption, leading to abnormal accumulation of ubiquitinated proteins. We identified UBE2E1, an E2 ubiquitin-conjugating enzyme that polyubiquitinates β-catenin, and RNF34, an E3 ligase, as novel interactants of MKS1. UBE2E1 and MKS1 colocalised, and loss of UBE2E1 recapitulates the ciliary and Wnt signalling phenotypes observed during loss of MKS1. Levels of UBE2E1 and MKS1 are co-dependent and UBE2E1 mediates both regulatory and degradative ubiquitination of MKS1. We demonstrate that processing of phosphorylated β-catenin occurs at the ciliary base through the functional interaction between UBE2E1 and MKS1. These observations suggest that correct β-catenin levels are tightly regulated at the primary cilium by a ciliary-specific E2 (UBE2E1) and a regulatory substrate-adaptor (MKS1).
Collapse
Affiliation(s)
- Katarzyna Szymanska
- Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom
| | - Karsten Boldt
- Institute of Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | | | - Matthew Adams
- Leeds Institute of Medical Research, University of Leeds, Leeds, United Kingdom
| | | | - Marius Ueffing
- Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Elton Zeqiraj
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| | - Gabrielle Wheway
- Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Colin A Johnson
- Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds, United Kingdom
| |
Collapse
|
15
|
Focșa IO, Budișteanu M, Burloiu C, Khan S, Sadeghpour A, Bohîlțea LC, Davis EE, Bălgrădean M. A case of Bardet-Biedl syndrome caused by a recurrent variant in BBS12: A case report. Biomed Rep 2021; 15:103. [PMID: 34760276 PMCID: PMC8567465 DOI: 10.3892/br.2021.1479] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Accepted: 09/29/2021] [Indexed: 12/30/2022] Open
Abstract
Bardet-Biedl syndrome (BBS) is a clinically and genetically heterogenous disorder that manifests as a result of primary cilia impairment. Cilia are present on most cell types, thus BBS is a multisystemic condition involving the majority of organ systems. The core features of the syndrome include retinal degeneration, obesity, polydactyly, cognitive impairment, renal anomalies and urogenital malformations. To date, pathogenic variants in 26 genes have been shown to be involved in the molecular basis of this rare ciliopathy. Of these causal loci, BBS12 accounts for ~8% of all cases. In this case report, an individual with BBS caused by a rare recurrent variant in BBS12 (NM_152618.3: c.1063C>T; p.Arg355*) is described and compared with others with the same DNA variant, placing this finding in the context of the current literature.
Collapse
Affiliation(s)
- Ina Ofelia Focșa
- Department of Medical Genetics, University of Medicine and Pharmacy 'Carol Davila', 021901 Bucharest, Romania
| | - Magdalena Budișteanu
- Department of Pediatric Neurology, 'Prof. Dr. Alexandru Obregia' Clinical Hospital of Psychiatry, 041914 Bucharest, Romania.,Medical Genetic Laboratory, 'Victor Babeș' National Institute of Pathology, 050096 Bucharest, Romania.,Department of Medical Genetics, Titu Maiorescu University, 040441 Bucharest, Romania
| | - Carmen Burloiu
- Department of Pediatric Neurology, 'Prof. Dr. Alexandru Obregia' Clinical Hospital of Psychiatry, 041914 Bucharest, Romania
| | - Sheraz Khan
- National Institute for Biotechnology and Genetic Engineering (NIBGE-C), Faisalabad, Pakistan Institute of Engineering and Applied Sciences, Islamabad 38000, Pakistan.,Advanced Center for Translational and Genetic Medicine, Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA
| | - Azita Sadeghpour
- Center for Human Disease Modeling, Duke University Medical Center, Durham, NC 27701, USA.,Duke Center for Applied Genomics and Precision Medicine, Duke University, Durham, NC 27708, USA
| | - Laurențiu C Bohîlțea
- Department of Medical Genetics, University of Medicine and Pharmacy 'Carol Davila', 021901 Bucharest, Romania
| | - Erica E Davis
- Advanced Center for Translational and Genetic Medicine, Stanley Manne Children's Research Institute, Ann and Robert H. Lurie Children's Hospital of Chicago, Chicago, IL 60611, USA.,Departments of Pediatrics and Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Mihaela Bălgrădean
- Department of Pediatrics and Pediatric Nephrology, Emergency Clinical Hospital for Children 'Maria Skłodowska Curie', 077120 Bucharest, Romania.,Department of Pediatrics, University of Medicine and Pharmacy 'Carol Davila', 077120 Bucharest, Romania
| |
Collapse
|
16
|
Liu D, Qian D, Shen H, Gong D. Structure of the human Meckel-Gruber protein Meckelin. SCIENCE ADVANCES 2021; 7:eabj9748. [PMID: 34731008 PMCID: PMC8565905 DOI: 10.1126/sciadv.abj9748] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Mutations in the Meckelin gene account for most cases of the Meckel-Gruber syndrome, the most severe ciliopathy with a 100% mortality rate. Here, we report a 3.3-Å cryo–electron microscopy structure of human Meckelin (also known as TMEM67 and MKS3). The structure reveals a unique protein fold consisting of an unusual cysteine-rich domain that folds as an arch bridge stabilized by 11 pairs of disulfide bonds, a previously uncharacterized domain named β sheet–rich domain, a previously unidentified seven-transmembrane fold wherein TM4 to TM6 are broken near the cytoplasmic surface of the membrane, and a coiled-coil domain placed below the transmembrane domain. Meckelin forms a stable homodimer with an extensive dimer interface. Our structure establishes a framework for dissecting the function and disease mechanisms of Meckelin.
Collapse
Affiliation(s)
- Dongliang Liu
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Dandan Qian
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China
| | - Huaizong Shen
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, Hangzhou, Zhejiang 310024, China
- Westlake Laboratory of Life Sciences and Biomedicine, Hangzhou, Zhejiang 310024, China
- Institute of Biology, Westlake Institute for Advanced Study, Hangzhou, Zhejiang 310024, China
| | - Deshun Gong
- State Key Laboratory of Medicinal Chemical Biology and College of Life Sciences, Nankai University, Tianjin 300350, China
- Corresponding author.
| |
Collapse
|
17
|
Potter VL, Moye AR, Robichaux MA, Wensel TG. Super-resolution microscopy reveals photoreceptor-specific subciliary location and function of ciliopathy-associated protein CEP290. JCI Insight 2021; 6:e145256. [PMID: 34520396 PMCID: PMC8564900 DOI: 10.1172/jci.insight.145256] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 09/08/2021] [Indexed: 01/19/2023] Open
Abstract
Mutations in the cilium-associated protein CEP290 cause retinal degeneration as part of multiorgan ciliopathies or as retina-specific diseases. The precise location and the functional roles of CEP290 within cilia and, specifically, the connecting cilia (CC) of photoreceptors, remain unclear. We used super-resolution fluorescence microscopy and electron microscopy to localize CEP290 in the CC and in the primary cilia of cultured cells with subdiffraction resolution and to determine effects of CEP290 deficiency in 3 mutant models. Radially, CEP290 localizes in close proximity to the microtubule doublets in the region between the doublets and the ciliary membrane. Longitudinally, it is distributed throughout the length of the CC whereas it is confined to the very base of primary cilia in human retinal pigment epithelium-1 cells. We found Y-shaped links, ciliary substructures between microtubules and membrane, throughout the length of the CC. Severe CEP290 deficiencies in mouse models did not prevent assembly of cilia or cause obvious mislocalization of ciliary components in early stages of degeneration. There were fewer cilia and no normal outer segments in the mutants, but the Y-shaped links were clearly present. These results point to photoreceptor-specific functions of CEP290 essential for CC maturation and stability following the earliest stages of ciliogenesis.
Collapse
Affiliation(s)
- Valencia L Potter
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology.,Program in Developmental Biology, Graduate School of Biomedical Sciences, and.,Medical Scientist Training Program, Baylor College of Medicine, Houston, Texas, USA
| | - Abigail R Moye
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology
| | - Michael A Robichaux
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology.,Departments of Ophthalmology and Biochemistry, West Virginia University School of Medicine, Morgantown, West Virginia, USA
| | - Theodore G Wensel
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology
| |
Collapse
|
18
|
Roopasree OJ, Adivitiya, Chakraborty S, Kateriya S, Veleri S. Centriole is the pivot coordinating dynamic signaling for cell proliferation and organization during early development in the vertebrates. Cell Biol Int 2021; 45:2178-2197. [PMID: 34288241 DOI: 10.1002/cbin.11667] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2021] [Accepted: 07/12/2021] [Indexed: 11/07/2022]
Abstract
Vertebrates have an elaborate and functionally segmented body. It evolves from a single cell by systematic cell proliferation but attains a complex body structure with exquisite precision. This development requires two cellular events: cell cycle and ciliogenesis. For these events, the dynamic molecular signaling is converged at the centriole. The cell cycle helps in cell proliferation and growth of the body and is a highly regulated and integrated process. Its errors cause malignancies and developmental disorders. The cells newly proliferated are organized during organogenesis. For a cellular organization, dedicated signaling hubs are developed in the cells, and most often cilia are utilized. The cilium is generated from one of the centrioles involved in cell proliferation. The developmental signaling pathways hosted in cilia are essential for the elaboration of the body plan. The cilium's compartmental seclusion is ideal for noise-free molecular signaling and is essential for the precision of the body layout. The dysfunctional centrioles and primary cilia distort the development of body layout that manifest as serious developmental disorders. Thus, centriole has a dual role in the growth and cellular organization. It organizes dynamically expressed molecules of cell cycle and ciliogenesis and plays a balancing act to generate new cells and organize them during development. A putative master molecule may regulate and coordinate the dynamic gene expression at the centrioles. The convergence of many critical signaling components at the centriole reiterates the idea that centriole is a major molecular workstation involved in elaborating the structural design and complexity in vertebrates. This article is protected by copyright. All rights reserved.
Collapse
Affiliation(s)
- O J Roopasree
- Agroprocessing Technology Division, CSIR-National Institute of Interdisciplinary Science and Technology, Thiruvananthapuram, Kerala 695019 and Academy of CSIR, Uttar Pradesh - 201002, India
| | - Adivitiya
- Laboratory of Optobiology, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Soura Chakraborty
- Laboratory of Optobiology, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Suneel Kateriya
- Laboratory of Optobiology, School of Biotechnology, Jawaharlal Nehru University, New Delhi, 110067, India
| | - Shobi Veleri
- Drug Safety Division, ICMR-National Institute of Nutrition, Hyderabad, 500007, India
| |
Collapse
|
19
|
Hazime KS, Zhou Z, Joachimiak E, Bulgakova NA, Wloga D, Malicki JJ. STORM imaging reveals the spatial arrangement of transition zone components and IFT particles at the ciliary base in Tetrahymena. Sci Rep 2021; 11:7899. [PMID: 33846423 PMCID: PMC8041816 DOI: 10.1038/s41598-021-86909-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Accepted: 03/22/2021] [Indexed: 11/17/2022] Open
Abstract
The base of the cilium comprising the transition zone (TZ) and transition fibers (TF) acts as a selecting gate to regulate the intraflagellar transport (IFT)-dependent trafficking of proteins to and from cilia. Before entering the ciliary compartment, IFT complexes and transported cargoes accumulate at or near the base of the cilium. The spatial organization of IFT proteins at the cilia base is key for understanding cilia formation and function. Using stochastic optical reconstruction microscopy (STORM) and computational averaging, we show that seven TZ, nine IFT, three Bardet–Biedl syndrome (BBS), and one centrosomal protein, form 9-clustered rings at the cilium base of a ciliate Tetrahymena thermophila. In the axial dimension, analyzed TZ proteins localize to a narrow region of about 30 nm while IFT proteins dock approximately 80 nm proximal to TZ. Moreover, the IFT-A subcomplex is positioned peripheral to the IFT-B subcomplex and the investigated BBS proteins localize near the ciliary membrane. The positioning of the HA-tagged N- and C-termini of the selected proteins enabled the prediction of the spatial orientation of protein particles and likely cargo interaction sites. Based on the obtained data, we built a comprehensive 3D-model showing the arrangement of the investigated ciliary proteins.
Collapse
Affiliation(s)
- Khodor S Hazime
- Bateson Centre and the Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
| | - Zhu Zhou
- Bateson Centre and the Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| | - Ewa Joachimiak
- Laboratory of Cytoskeleton and Cilia Biology, 3 Pasteur Street, 02-093, Warsaw, Poland
| | - Natalia A Bulgakova
- Bateson Centre and the Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK.
| | - Dorota Wloga
- Laboratory of Cytoskeleton and Cilia Biology, 3 Pasteur Street, 02-093, Warsaw, Poland.
| | - Jarema J Malicki
- Bateson Centre and the Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield, S10 2TN, UK
| |
Collapse
|
20
|
Zhu P, Qiu Q, Harris PC, Xu X, Lin X. mtor Haploinsufficiency Ameliorates Renal Cysts and Cilia Abnormality in Adult Zebrafish tmem67 Mutants. J Am Soc Nephrol 2021; 32:822-836. [PMID: 33574160 PMCID: PMC8017545 DOI: 10.1681/asn.2020070991] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 12/21/2020] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND Although zebrafish embryos have been used to study ciliogenesis and model polycystic kidney disease (PKD), adult zebrafish remain unexplored. METHODS Transcription activator-like effector nucleases (TALEN) technology was used to generate mutant for tmem67, the homolog of the mammalian causative gene for Meckel syndrome type 3 (MKS3). Classic 2D and optical-clearing 3D imaging of an isolated adult zebrafish kidney were used to examine cystic and ciliary phenotypes. A hypomorphic mtor strain or rapamycin was used to inhibit mTOR activity. RESULTS Adult tmem67 zebrafish developed progressive mesonephric cysts that share conserved features of mammalian cystogenesis, including a switch of cyst origin with age and an increase in proliferation of cyst-lining epithelial cells. The mutants had shorter and fewer distal single cilia and greater numbers of multiciliated cells (MCCs). Absence of a single cilium preceded cystogenesis, and expansion of MCCs occurred after pronephric cyst formation and was inversely correlated with the severity of renal cysts in young adult zebrafish, suggesting a primary defect and an adaptive action, respectively. Finally, the mutants exhibited hyperactive mTOR signaling. mTOR inhibition ameliorated renal cysts in both the embryonic and adult zebrafish models; however, it only rescued ciliary abnormalities in the adult mutants. CONCLUSIONS Adult zebrafish tmem67 mutants offer a new vertebrate model for renal cystic diseases, in which cilia morphology can be analyzed at a single-nephron resolution and mTOR inhibition proves to be a candidate therapeutic strategy.
Collapse
Affiliation(s)
- Ping Zhu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota
| | - Qi Qiu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota
| | - Peter C. Harris
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota,Division of Nephrology and Hypertension, Mayo Clinic, Rochester, Minnesota
| | - Xiaolei Xu
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota,Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota
| | - Xueying Lin
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, Minnesota
| |
Collapse
|
21
|
Sánchez-Bellver L, Toulis V, Marfany G. On the Wrong Track: Alterations of Ciliary Transport in Inherited Retinal Dystrophies. Front Cell Dev Biol 2021; 9:623734. [PMID: 33748110 PMCID: PMC7973215 DOI: 10.3389/fcell.2021.623734] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/09/2021] [Indexed: 01/14/2023] Open
Abstract
Ciliopathies are a group of heterogeneous inherited disorders associated with dysfunction of the cilium, a ubiquitous microtubule-based organelle involved in a broad range of cellular functions. Most ciliopathies are syndromic, since several organs whose cells produce a cilium, such as the retina, cochlea or kidney, are affected by mutations in ciliary-related genes. In the retina, photoreceptor cells present a highly specialized neurosensory cilium, the outer segment, stacked with membranous disks where photoreception and phototransduction occurs. The daily renewal of the more distal disks is a unique characteristic of photoreceptor outer segments, resulting in an elevated protein demand. All components necessary for outer segment formation, maintenance and function have to be transported from the photoreceptor inner segment, where synthesis occurs, to the cilium. Therefore, efficient transport of selected proteins is critical for photoreceptor ciliogenesis and function, and any alteration in either cargo delivery to the cilium or intraciliary trafficking compromises photoreceptor survival and leads to retinal degeneration. To date, mutations in more than 100 ciliary genes have been associated with retinal dystrophies, accounting for almost 25% of these inherited rare diseases. Interestingly, not all mutations in ciliary genes that cause retinal degeneration are also involved in pleiotropic pathologies in other ciliated organs. Depending on the mutation, the same gene can cause syndromic or non-syndromic retinopathies, thus emphasizing the highly refined specialization of the photoreceptor neurosensory cilia, and raising the possibility of photoreceptor-specific molecular mechanisms underlying common ciliary functions such as ciliary transport. In this review, we will focus on ciliary transport in photoreceptor cells and discuss the molecular complexity underpinning retinal ciliopathies, with a special emphasis on ciliary genes that, when mutated, cause either syndromic or non-syndromic retinal ciliopathies.
Collapse
Affiliation(s)
- Laura Sánchez-Bellver
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
| | - Vasileios Toulis
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- CIBERER, ISCIII, Universitat de Barcelona, Barcelona, Spain
| | - Gemma Marfany
- Departament de Genètica, Microbiologia i Estadística, Universitat de Barcelona, Barcelona, Spain
- Institute of Biomedicine (IBUB-IRSJD), Universitat de Barcelona, Barcelona, Spain
- CIBERER, ISCIII, Universitat de Barcelona, Barcelona, Spain
| |
Collapse
|
22
|
Smith CEL, Lake AVR, Johnson CA. Primary Cilia, Ciliogenesis and the Actin Cytoskeleton: A Little Less Resorption, A Little More Actin Please. Front Cell Dev Biol 2020; 8:622822. [PMID: 33392209 PMCID: PMC7773788 DOI: 10.3389/fcell.2020.622822] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 11/24/2020] [Indexed: 12/13/2022] Open
Abstract
Primary cilia are microtubule-based organelles that extend from the apical surface of most mammalian cells, forming when the basal body (derived from the mother centriole) docks at the apical cell membrane. They act as universal cellular “antennae” in vertebrates that receive and integrate mechanical and chemical signals from the extracellular environment, serving diverse roles in chemo-, mechano- and photo-sensation that control developmental signaling, cell polarity and cell proliferation. Mutations in ciliary genes cause a major group of inherited developmental disorders called ciliopathies. There are very few preventative treatments or new therapeutic interventions that modify disease progression or the long-term outlook of patients with these conditions. Recent work has identified at least four distinct but interrelated cellular processes that regulate cilia formation and maintenance, comprising the cell cycle, cellular proteostasis, signaling pathways and structural influences of the actin cytoskeleton. The actin cytoskeleton is composed of microfilaments that are formed from filamentous (F) polymers of globular G-actin subunits. Actin filaments are organized into bundles and networks, and are attached to the cell membrane, by diverse cross-linking proteins. During cell migration, actin filament bundles form either radially at the leading edge or as axial stress fibers. Early studies demonstrated that loss-of-function mutations in ciliopathy genes increased stress fiber formation and impaired ciliogenesis whereas pharmacological inhibition of actin polymerization promoted ciliogenesis. These studies suggest that polymerization of the actin cytoskeleton, F-actin branching and the formation of stress fibers all inhibit primary cilium formation, whereas depolymerization or depletion of actin enhance ciliogenesis. Here, we review the mechanistic basis for these effects on ciliogenesis, which comprise several cellular processes acting in concert at different timescales. Actin polymerization is both a physical barrier to both cilia-targeted vesicle transport and to the membrane remodeling required for ciliogenesis. In contrast, actin may cause cilia loss by localizing disassembly factors at the ciliary base, and F-actin branching may itself activate the YAP/TAZ pathway to promote cilia disassembly. The fundamental role of actin polymerization in the control of ciliogenesis may present potential new targets for disease-modifying therapeutic approaches in treating ciliopathies.
Collapse
Affiliation(s)
- Claire E L Smith
- Leeds Institute of Medical Research at St. James's, University of Leeds, Leeds, United Kingdom
| | - Alice V R Lake
- Leeds Institute of Medical Research at St. James's, University of Leeds, Leeds, United Kingdom
| | - Colin A Johnson
- Leeds Institute of Medical Research at St. James's, University of Leeds, Leeds, United Kingdom
| |
Collapse
|
23
|
Luo M, He R, Lin Z, Shen Y, Zhang G, Cao Z, Lu C, Meng D, Zhang J, Ma X, Cao M. Novel Compound Heterozygous Variants in MKS1 Leading to Joubert Syndrome. Front Genet 2020; 11:576235. [PMID: 33193692 PMCID: PMC7592398 DOI: 10.3389/fgene.2020.576235] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2020] [Accepted: 09/14/2020] [Indexed: 11/13/2022] Open
Abstract
Joubert syndrome (JBTS) and Meckel-Gruber syndrome (MKS) are rare recessive disorders caused by defects of cilia, and they share overlapping clinical features and allelic loci. Mutations of MKS1 contribute approximately 7% to all MKS cases and are found in some JBTS patients. Here, we describe a JBTS patient with two novel mutations of MKS1. Whole exome sequencing (WES) revealed c.191-1G > A and c.1058delG compound heterozygous variants. The patient presented with typical cerebellar vermis hypoplasia, hypotonia, and developmental delay, but without other renal/hepatic involvement or polydactyly. Functional studies showed that the c.1058delG mutation disrupts the B9 domain of MKS1, attenuates the interactions with B9D2, and impairs its ciliary localization at the transition zone (TZ), indicating that the B9 domain of MKS1 is essential for the integrity of the B9 protein complex and localization of MKS1 at the TZ. This work expands the mutation spectrum of MKS1 and elucidates the clinical heterogeneity of MKS1-related ciliopathies.
Collapse
Affiliation(s)
- Minna Luo
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Ruida He
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Zaisheng Lin
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Yue Shen
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Guangyu Zhang
- Department of Children Rehabilitation, The Third Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zongfu Cao
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Chao Lu
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Dan Meng
- Tianjin Key Laboratory of Food and Biotechnology, School of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin, China
| | - Jing Zhang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xu Ma
- National Research Institute for Family Planning, Beijing, China.,National Human Genetic Resources Center, Beijing, China
| | - Muqing Cao
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Department of Pathophysiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| |
Collapse
|
24
|
Chen HY, Kelley RA, Li T, Swaroop A. Primary cilia biogenesis and associated retinal ciliopathies. Semin Cell Dev Biol 2020; 110:70-88. [PMID: 32747192 PMCID: PMC7855621 DOI: 10.1016/j.semcdb.2020.07.013] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 07/14/2020] [Accepted: 07/18/2020] [Indexed: 12/19/2022]
Abstract
The primary cilium is a ubiquitous microtubule-based organelle that senses external environment and modulates diverse signaling pathways in different cell types and tissues. The cilium originates from the mother centriole through a complex set of cellular events requiring hundreds of distinct components. Aberrant ciliogenesis or ciliary transport leads to a broad spectrum of clinical entities with overlapping yet highly variable phenotypes, collectively called ciliopathies, which include sensory defects and syndromic disorders with multi-organ pathologies. For efficient light detection, photoreceptors in the retina elaborate a modified cilium known as the outer segment, which is packed with membranous discs enriched for components of the phototransduction machinery. Retinopathy phenotype involves dysfunction and/or degeneration of the light sensing photoreceptors and is highly penetrant in ciliopathies. This review will discuss primary cilia biogenesis and ciliopathies, with a focus on the retina, and the role of CP110-CEP290-CC2D2A network. We will also explore how recent technologies can advance our understanding of cilia biology and discuss new paradigms for developing potential therapies of retinal ciliopathies.
Collapse
Affiliation(s)
- Holly Y Chen
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA.
| | - Ryan A Kelley
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Tiansen Li
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA
| | - Anand Swaroop
- Neurobiology, Neurodegeneration and Repair Laboratory, National Eye Institute, National Institutes of Health, MSC0610, 6 Center Drive, Bethesda, MD 20892, USA.
| |
Collapse
|
25
|
Exploring Key Challenges of Understanding the Pathogenesis of Kidney Disease in Bardet-Biedl Syndrome. Kidney Int Rep 2020; 5:1403-1415. [PMID: 32954066 PMCID: PMC7486190 DOI: 10.1016/j.ekir.2020.06.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/04/2020] [Accepted: 06/17/2020] [Indexed: 12/21/2022] Open
Abstract
Bardet–Biedl syndrome (BBS) is a rare pleiotropic inherited disorder known as a ciliopathy. Kidney disease is a cardinal clinical feature; however, it is one of the less investigated traits. This study is a comprehensive analysis of the literature aiming to collect available information providing mechanistic insights into the pathogenesis of kidney disease by analyzing clinical and basic science studies focused on this issue. The analysis revealed that the syndrome is either clinically and genetically heterogenous, with 24 genes discovered to date, but with 3 genes (BBS1, BBS2, and BBS10) accounting for almost 50% of diagnoses; genotype–phenotype correlation studies showed that patients with BBS1 mutations have a less severe renal phenotype than the other 2 most common loci; in addition, truncating rather than missense mutations are more likely to cause kidney disease. However, significant intrafamilial clinical variability has been described, with no clear explanation to date. In mice kidneys, Bbs genes have relative low expression levels, in contrast with other common affected organs, like the retina; surprisingly, Bbs1 is the only locus with basal overexpression in the kidney. In vitro studies indicate that signalling pathways involved in embryonic kidney development and repair are affected in the context of BBS depletion; in mice, kidney disease does not have a full penetrance; when present, it resembles human phenotype and shows an age-dependent progression. Data on the exact contribution of local versus systemic consequences of Bbs dysfunction are scanty and further investigations are required to get firm conclusions.
Collapse
|
26
|
Yu T, Matsuda M. Epb41l5 interacts with Iqcb1 and regulates ciliary function in zebrafish embryos. J Cell Sci 2020; 133:jcs240648. [PMID: 32501287 PMCID: PMC7338265 DOI: 10.1242/jcs.240648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 05/13/2020] [Indexed: 11/20/2022] Open
Abstract
Erythrocyte protein band 4.1 like 5 (EPB41L5) is an adaptor protein beneath the plasma membrane that functions to control epithelial morphogenesis. Here we report a previously uncharacterized role of EPB41L5 in controlling ciliary function. We found that EPB41L5 forms a complex with IQCB1 (previously known as NPHP5), a ciliopathy protein. Overexpression of EPB41L5 reduced IQCB1 localization at the ciliary base in cultured mammalian epithelial cells. Conversely, epb41l5 knockdown increased IQCB1 localization at the ciliary base. epb41l5-deficient zebrafish embryos or embryos expressing C-terminally modified forms of Epb41l5 developed cilia with reduced motility and exhibited left-right patterning defects, an outcome of abnormal ciliary function. We observed genetic synergy between epb41l5 and iqcb1. Moreover, EPB41L5 decreased IQCB1 interaction with CEP290, another ciliopathy protein and a component of the ciliary base and centrosome. Together, these observations suggest that EPB41L5 regulates the composition of the ciliary base and centrosome through IQCB1 and CEP290.
Collapse
Affiliation(s)
- Tiffany Yu
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07302, USA
| | - Miho Matsuda
- Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ 07302, USA
- Department of Cell, Developmental and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| |
Collapse
|
27
|
Alfieri M, Iaconis D, Tammaro R, Perone L, Calì G, Nitsch L, Dougherty GW, Ragnini-Wilson A, Franco B. The centrosomal/basal body protein OFD1 is required for microtubule organization and cell cycle progression. Tissue Cell 2020; 64:101369. [PMID: 32473706 DOI: 10.1016/j.tice.2020.101369] [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: 09/24/2019] [Revised: 04/14/2020] [Accepted: 04/14/2020] [Indexed: 12/28/2022]
Abstract
Oral-Facial-Digital type I (OFD1) is a rare inherited form of renal cystic disease associated with ciliary dysfunction. This disorder is due to mutations in the OFD1 gene that encodes a protein localized to centrosomes and basal bodies in different cell types. Immunofluorescence analysis demonstrated that OFD1 displays a dynamic distribution during cell cycle. High-content microscopy analysis of Ofd1-depleted fibroblasts revealed impaired cell cycle progression. Immunofluorescence analysis and cell proliferation assays also indicated the presence of a variety of defects such as centrosome accumulation, nuclear abnormalities and aneuploidy. In addition, Ofd1-depleted cells displayed an abnormal microtubule network that may underlie these defects. All together our results suggest that OFD1 contributes to the function of the microtubule organizing center (MTOC) in the cell, controlling cell cycle progression both in vitro and in vivo.
Collapse
Affiliation(s)
- Mariaevelina Alfieri
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei, 34, 80078, Pozzuoli, Naples, Italy
| | - Daniela Iaconis
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei, 34, 80078, Pozzuoli, Naples, Italy
| | - Roberta Tammaro
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei, 34, 80078, Pozzuoli, Naples, Italy
| | - Lucia Perone
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei, 34, 80078, Pozzuoli, Naples, Italy
| | - Gaetano Calì
- National Research Council - Institute of Experimental Endocrinology and Oncology, Naples, Italy
| | - Lucio Nitsch
- Department of Molecular Medicine and Medical Biotechnology, University of Naples "Federico II", Naples, Italy
| | - Gerard W Dougherty
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei, 34, 80078, Pozzuoli, Naples, Italy; Department of General Pediatrics, University Hospital Muenster, 48149, Muenster, Germany
| | | | - Brunella Franco
- Telethon Institute of Genetics and Medicine (TIGEM), Via Campi Flegrei, 34, 80078, Pozzuoli, Naples, Italy; Medical Genetics, Department of Translational Medicine, University of Naples "Federico II", Via Sergio Pansini, 80131, Naples, Italy.
| |
Collapse
|
28
|
Ciliary Genes in Renal Cystic Diseases. Cells 2020; 9:cells9040907. [PMID: 32276433 PMCID: PMC7226761 DOI: 10.3390/cells9040907] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 03/27/2020] [Accepted: 04/05/2020] [Indexed: 12/28/2022] Open
Abstract
Cilia are microtubule-based organelles, protruding from the apical cell surface and anchoring to the cytoskeleton. Primary (nonmotile) cilia of the kidney act as mechanosensors of nephron cells, responding to fluid movements by triggering signal transduction. The impaired functioning of primary cilia leads to formation of cysts which in turn contribute to development of diverse renal diseases, including kidney ciliopathies and renal cancer. Here, we review current knowledge on the role of ciliary genes in kidney ciliopathies and renal cell carcinoma (RCC). Special focus is given on the impact of mutations and altered expression of ciliary genes (e.g., encoding polycystins, nephrocystins, Bardet-Biedl syndrome (BBS) proteins, ALS1, Oral-facial-digital syndrome 1 (OFD1) and others) in polycystic kidney disease and nephronophthisis, as well as rare genetic disorders, including syndromes of Joubert, Meckel-Gruber, Bardet-Biedl, Senior-Loken, Alström, Orofaciodigital syndrome type I and cranioectodermal dysplasia. We also show that RCC and classic kidney ciliopathies share commonly disturbed genes affecting cilia function, including VHL (von Hippel-Lindau tumor suppressor), PKD1 (polycystin 1, transient receptor potential channel interacting) and PKD2 (polycystin 2, transient receptor potential cation channel). Finally, we discuss the significance of ciliary genes as diagnostic and prognostic markers, as well as therapeutic targets in ciliopathies and cancer.
Collapse
|
29
|
Immunohistochemical expression of Napsin A in normal human fetal lungs at different gestational ages and in acquired and congenital pathological pulmonary conditions. Virchows Arch 2020; 477:557-563. [PMID: 32270298 DOI: 10.1007/s00428-020-02809-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 03/18/2020] [Accepted: 03/25/2020] [Indexed: 10/24/2022]
Abstract
Surfactant protein B (SP-B) is a key component of pulmonary surfactant. SP-B is processed to a mature, surface-active protein from a pro-peptide by two distinct cleavage events in its N-terminal and C-terminal regions. Napsin A, a protease expressed in type II pneumocytes, is responsible for the N-terminal cleavage event. Here, for the first time, we have evaluated the expression of Napsin A in normal fetal lungs at different gestational ages and in lungs from fetuses and neonates with congenital and acquired pathological pulmonary conditions. Lung samples were collected from fetal and neonatal autopsies at the Department of Medicine and Surgery's Pathology Unit of Parma University (Italy). Immunohistochemical analysis was performed using a primary anti-Napsin A (clone IP64 clone) monoclonal antibody. A section of lung adenocarcinoma was used as an external positive control. Napsin A was expressed early in normal fetal lungs throughout the epithelium of the distal pseudoglandular tracts. In fetuses at 30 weeks of gestation and term newborns, Napsin A was already expressed only in isolated cells within the alveolar epithelium, similar to adult subjects. Furthermore, increased expression of Napsin A compared with a control group was observed in lung tissue from fetuses and a newborn with pathological conditions (inflammatory diseases and pulmonary hypoplasia). In conclusion, this study demonstrates that Napsin A is produced early in fetal life, and that its production is increased in many diseases, presumably in an effort to remedy functional pulmonary failure.
Collapse
|
30
|
George A, Cogliati T, Brooks BP. Genetics of syndromic ocular coloboma: CHARGE and COACH syndromes. Exp Eye Res 2020; 193:107940. [PMID: 32032630 DOI: 10.1016/j.exer.2020.107940] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 01/20/2020] [Accepted: 01/22/2020] [Indexed: 02/07/2023]
Abstract
Optic fissure closure defects result in uveal coloboma, a potentially blinding condition affecting between 0.5 and 2.6 per 10,000 births that may cause up to 10% of childhood blindness. Uveal coloboma is on a phenotypic continuum with microphthalmia (small eye) and anophthalmia (primordial/no ocular tissue), the so-called MAC spectrum. This review gives a brief overview of the developmental biology behind coloboma and its clinical presentation/spectrum. Special attention will be given to two prominent, syndromic forms of coloboma, namely, CHARGE (Coloboma, Heart defect, Atresia choanae, Retarded growth and development, Genital hypoplasia, and Ear anomalies/deafness) and COACH (Cerebellar vermis hypoplasia, Oligophrenia, Ataxia, Coloboma, and Hepatic fibrosis) syndromes. Approaches employed to identify genes involved in optic fissure closure in animal models and recent advances in live imaging of zebrafish eye development are also discussed.
Collapse
Affiliation(s)
- Aman George
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health. Bethesda, Maryland, 20892, USA
| | - Tiziana Cogliati
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health. Bethesda, Maryland, 20892, USA
| | - Brian P Brooks
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health. Bethesda, Maryland, 20892, USA.
| |
Collapse
|
31
|
Zhang R, Chen S, Han P, Chen F, Kuang S, Meng Z, Liu J, Sun R, Wang Z, He X, Li Y, Guan Y, Yue Z, Li C, Kumar Dey S, Zhu Y, Banerjee S. Whole exome sequencing identified a homozygous novel variant in CEP290 gene causes Meckel syndrome. J Cell Mol Med 2019; 24:1906-1916. [PMID: 31840411 PMCID: PMC6991682 DOI: 10.1111/jcmm.14887] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 11/15/2019] [Accepted: 11/22/2019] [Indexed: 12/01/2022] Open
Abstract
Meckel syndrome (MKS) is a pre‐ or perinatal multisystemic ciliopathic lethal disorder with an autosomal recessive mode of inheritance. Meckel syndrome is usually manifested with meningo‐occipital encephalocele, polycystic kidney dysplasia, postaxial polydactyly and hepatobiliary ductal plate malformation. Germline variants in CEP290 cause MKS4. In this study, we investigated a 35‐years‐old Chinese female who was 17+1 weeks pregnant. She had a history of adverse pregnancy of having foetus with multiple malformations. We performed ultrasonography and identified the foetus with occipital meningoencephalocele and enlarged cystic dysplastic kidneys. So, she decided to terminate her pregnancy and further genetic molecular analysis was performed. We identified the aborted foetus without postaxial polydactyly. Histological examination of foetal kidney showed cysts in kidney and thinning of the renal cortex with glomerular atrophy. Whole exome sequencing identified a novel homozygous variant (c.2144T>G; p.L715*) in exon 21 of the CEP290 in the foetus. Sanger sequencing confirmed that both the parents of the foetus were carrying this variant in a heterozygous state. This variant was not identified in two elder sisters of the foetus as well as in the 100 healthy individuals. Western blot analysis showed that this variant leads to the formation of truncated CEP290 protein with the molecular weight of 84 KD compared with the wild‐type CEP290 protein of 290 KD. Hence, it is a loss‐of‐function variant. We also found that the mutant cilium appears longer in length than the wild‐type cilium. Our present study reported the first variant of CEP290 associated with MKS4 in Chinese population.
Collapse
Affiliation(s)
- Rui Zhang
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Shaoyun Chen
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Peng Han
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Fangfang Chen
- Department of Pathology, Bao'an Maternity and Child Health Hospital, Shenzhen, China
| | - Shan Kuang
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Zhuo Meng
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Junnian Liu
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China.,BGI-Shenzhen, Beishan Industrial Zone, Shenzhen, China
| | - Ruliang Sun
- Department of Pathology, Bao'an Maternity and Child Health Hospital, Shenzhen, China
| | - Zhiwei Wang
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Xiaohong He
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Yong Li
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | - Yuanning Guan
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China
| | | | - Chen Li
- Department of Cell Biology and Medical Genetics, School of Medicine, Zhejiang University, Hangzhou, China
| | - Subrata Kumar Dey
- Department of Biotechnology, Centre for Genetic Studies, School of Biotechnology and Biological Sciences, Maulana Abul Kalam Azad University of Technology (Formerly West Bengal University of Technology), Kolkata, India.,Brainware University, Barasat, India
| | - Yuanfang Zhu
- Division of Maternal-Fetal Medicine, Bao'an Women and Children's Hospital, Jinan University, Shenzhen, China
| | - Santasree Banerjee
- BGI-Qingdao, BGI-Shenzhen, Qingdao, China.,China National GeneBank, BGI-Shenzhen, Shenzhen, China.,BGI-Shenzhen, Beishan Industrial Zone, Shenzhen, China.,Brainware University, Barasat, India
| |
Collapse
|
32
|
Glöcklhofer CR, Steinfurt J, Franke G, Hoppmann A, Glantschnig T, Perez-Feliz S, Alter S, Fischer J, Brunner M, Rainer PP, Köttgen A, Bode C, Odening KE. A novel LMNA nonsense mutation causes two distinct phenotypes of cardiomyopathy with high risk of sudden cardiac death in a large five-generation family. Europace 2019; 20:2003-2013. [PMID: 29947763 DOI: 10.1093/europace/euy127] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Accepted: 05/09/2018] [Indexed: 12/19/2022] Open
Abstract
Aims Characterization of the cardiac phenotype associated with the novel LMNA nonsense mutation c.544C>T, p.Q182*, which we have identified in a large five-generation family. Methods and results A family tree was constructed. Clinical data [arrhythmia, syncope, sudden cardiac death (SCD), New York Heart Association (NYHA) class] were collected from living and deceased family members. DNA of 23 living family members was analysed for mutations in LMNA. Additionally, dilated cardiomyopathy multi-gene-panel testing and whole exome sequencing were performed in some family members to identify potential phenotype-modifiers. In this five-generation family (n = 65), 17 SCDs occurred at 49.3 ± 10.0 years. Furthermore, we identified eight additional mutation-carriers, seven symptomatic (44 ± 13 years), and one asymptomatic (44 years). First signs of disease [sinus bradycardia with atrioventricular (AV)-block I°] occurred at 36.5 ± 8.1 years. Paroxysmal atrial fibrillation (AF) (onset at 41.8 ± 5.7 years) rapidly progressed to permanent AF (46.2 ± 9.8 years). Subsequently, AV-conduction worsened, syncope, pacemaker-dependence, and non-sustained ventricular tachycardia (43.3 ± 8.2 years) followed. Ventricular arrhythmia caused SCD in patients without implantable cardioverter-defibrillator (ICD). Patients protected by ICD developed rapidly progressive heart failure (45.2 ± 10.6 years). A different phenotype was seen in a sub-family in three patients with early onset of rapidly decompensating heart failure and only minor prior arrhythmia-related symptoms. One patient received high-urgency heart transplantation (HTX) at 32 years, while two died prior to HTX. One of them developed lethal peripartum-associated heart failure. Possible disease-modifiers were identified in this 'heart failure sub-family'. Conclusion The novel LMNA nonsense mutation c.544C>T causes a severe arrhythmogenic phenotype manifesting with high incidence of SCD in most patients; and in one sub-family, a distinct phenotype with fast progressing heart failure, indicating the need for early consideration of ICD-implantation and listing for heart-transplantation.
Collapse
Affiliation(s)
- Christina R Glöcklhofer
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Johannes Steinfurt
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Gerlind Franke
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Anselm Hoppmann
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute of Genetic Epidemiology, Medical Center University of Freiburg, Freiburg, Germany.,Genetics and Experimental Bioinformatics, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | | | - Stefanie Perez-Feliz
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Svenja Alter
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute of Human Genetics, Medical Center University of Freiburg, Freiburg, Germany
| | - Judith Fischer
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute of Human Genetics, Medical Center University of Freiburg, Freiburg, Germany
| | - Michael Brunner
- Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Peter P Rainer
- Division of Cardiology, Medical University of Graz, Graz, Austria
| | - Anna Köttgen
- Faculty of Medicine, University of Freiburg, Freiburg, Germany.,Institute of Genetic Epidemiology, Medical Center University of Freiburg, Freiburg, Germany
| | - Christoph Bode
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.,Faculty of Medicine, University of Freiburg, Freiburg, Germany
| |
Collapse
|
33
|
Characterization of Primary Cilia in Normal Fallopian Tube Epithelium and Serous Tubal Intraepithelial Carcinoma. Int J Gynecol Cancer 2019; 28:1535-1544. [PMID: 30095490 PMCID: PMC6166701 DOI: 10.1097/igc.0000000000001321] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Supplemental digital content is available in the text. Objectives The aim of this study was to investigate the distribution of primary cilia on secretory cells in normal fallopian tube (FT) and serous tubal intraepithelial carcinoma (STIC). Methods Fallopian tube tissue samples were obtained from 4 females undergoing prophylactic hysterectomies and 6 patients diagnosed with STIC. A mogp-TAg transgenic mouse STIC sample was also compared with a wild-type mouse FT sample. Serous tubal intraepithelial carcinoma was identified by hematoxylin and eosin staining and confirmed by positive Ki-67 and p53 immunohistochemical staining of tissue sections. We assessed the relative distribution of primary cilia on secretory cells and motile cilia on multiple ciliated cells by immunofluorescence and immunohistochemical staining. Ciliary function was assessed by immunofluorescence staining of specific ciliary marker proteins and responsiveness to Sonic Hedgehog signaling. Results Primary cilia are widespread on secretory cells in the ampulla, isthmus, and in particular, the fimbriae of human FT where they may appear to mediate ciliary-mediated Sonic Hedgehog signaling. A statistically significant reduction in the number of primary cilia on secretory cells was observed in human STIC samples compared with normal controls (P < 0.0002, Student t test), supported by similar findings in a mouse STIC sample. Immunohistochemical staining for dynein axonemal heavy chain 5 discriminated multiple motile cilia from primary cilia in human FT. Conclusions Primary cilia are widespread on secretory cells in the ampulla, isthmus, and in particular, the fimbriae of the human FT but are significantly reduced in both human and mouse STIC samples. Immunohistochemical staining for ciliary proteins may have clinical utility for early detection of STIC.
Collapse
|
34
|
Cilia and development. Curr Opin Genet Dev 2019; 56:15-21. [DOI: 10.1016/j.gde.2019.05.002] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/07/2019] [Accepted: 05/11/2019] [Indexed: 01/01/2023]
|
35
|
Abstract
For over a century, the centrosome has been an organelle more easily tracked than understood, and the study of its peregrinations within the cell remains a chief underpinning of its functional investigation. Increasing attention and new approaches have been brought to bear on mechanisms that control centrosome localization in the context of cleavage plane determination, ciliogenesis, directional migration, and immunological synapse formation, among other cellular and developmental processes. The Golgi complex, often linked with the centrosome, presents a contrasting case of a pleiomorphic organelle for which functional studies advanced somewhat more rapidly than positional tracking. However, Golgi orientation and distribution has emerged as an area of considerable interest with respect to polarized cellular function. This chapter will review our current understanding of the mechanism and significance of the positioning of these organelles.
Collapse
|
36
|
Roman AC, Garrido-Jimenez S, Diaz-Chamorro S, Centeno F, Carvajal-Gonzalez JM. Centriole Positioning: Not Just a Little Dot in the Cell. Results Probl Cell Differ 2019; 67:201-221. [PMID: 31435796 DOI: 10.1007/978-3-030-23173-6_8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Organelle positioning as many other morphological parameters in a cell is not random. Centriole positioning as centrosomes or ciliary basal bodies is not an exception to this rule in cell biology. Indeed, centriole positioning is a tightly regulated process that occurs during development, and it is critical for many organs to function properly, not just during development but also in the adulthood. In this book chapter, we overview our knowledge on centriole positioning in different and highly specialized animal cells like photoreceptor or ependymal cells. We will also discuss recent advances in the discovery of molecular pathways involved in this process, mostly related to the cytoskeleton and the cell polarity pathways. And finally, we present quantitative methods that have been used to assess centriole positioning in different cell types although mostly in epithelial cells.
Collapse
Affiliation(s)
- Angel-Carlos Roman
- Facultad de Ciencias, Departamento de Bioquímica, Biología Molecular y Genética, Universidad de Extremadura, Badajoz, Spain
| | - Sergio Garrido-Jimenez
- Facultad de Ciencias, Departamento de Bioquímica, Biología Molecular y Genética, Universidad de Extremadura, Badajoz, Spain
| | - Selene Diaz-Chamorro
- Facultad de Ciencias, Departamento de Bioquímica, Biología Molecular y Genética, Universidad de Extremadura, Badajoz, Spain
| | - Francisco Centeno
- Facultad de Ciencias, Departamento de Bioquímica, Biología Molecular y Genética, Universidad de Extremadura, Badajoz, Spain
| | - Jose Maria Carvajal-Gonzalez
- Facultad de Ciencias, Departamento de Bioquímica, Biología Molecular y Genética, Universidad de Extremadura, Badajoz, Spain.
| |
Collapse
|
37
|
Huynh JM, Galindo M, Laukaitis CM. Missense variants in TMEM67 in a patient with Joubert syndrome. Clin Case Rep 2018; 6:2189-2192. [PMID: 30455918 PMCID: PMC6230611 DOI: 10.1002/ccr3.1748] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 06/30/2018] [Accepted: 07/08/2018] [Indexed: 11/11/2022] Open
Abstract
We present a patient with a clinical diagnosis of Joubert syndrome with COACH phenotype who carries two TMEM67 variants of uncertain significance (VUS). One VUS can be reclassified as "likely pathogenic" by adding clinical data. As genetic testing becomes more accessible, more VUS will require clinical correlation for accurate classification.
Collapse
Affiliation(s)
| | | | - Christina M. Laukaitis
- Department of MedicineCenter for Applied Genetics and GenomicsCollege of MedicineUniversity of Arizona Cancer CenterUniversity of ArizonaTucsonArizona
| |
Collapse
|
38
|
Falk N, Kessler K, Schramm SF, Boldt K, Becirovic E, Michalakis S, Regus-Leidig H, Noegel AA, Ueffing M, Thiel CT, Roepman R, Brandstätter JH, Gießl A. Functional analyses of Pericentrin and Syne-2 interaction in ciliogenesis. J Cell Sci 2018; 131:jcs.218487. [PMID: 30054381 DOI: 10.1242/jcs.218487] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 07/12/2018] [Indexed: 01/31/2023] Open
Abstract
Pericentrin (Pcnt) is a multifunctional scaffold protein and mutations in the human PCNT gene are associated with several diseases, including ciliopathies. Pcnt plays a crucial role in ciliary development in olfactory receptor neurons, but its function in the photoreceptor-connecting cilium is unknown. We downregulated Pcnt in the retina ex vivo and in vivo via a virus-based RNA interference approach to study Pcnt function in photoreceptors. ShRNA-mediated knockdown of Pcnt impaired the development of the connecting cilium and the outer segment of photoreceptors, and caused a nuclear migration defect. In protein interaction screens, we found that the outer nuclear membrane protein Syne-2 (also known as Nesprin-2) is an interaction partner of Pcnt in photoreceptors. Syne-2 is important for positioning murine photoreceptor cell nuclei and for centrosomal migration during early ciliogenesis. CRISPR/Cas9-mediated knockout of Syne-2 in cell culture led to an overexpression and mislocalization of Pcnt and to ciliogenesis defects. Our findings suggest that the Pcnt-Syne-2 complex is important for ciliogenesis and outer segment formation during retinal development and plays a role in nuclear migration.
Collapse
Affiliation(s)
- Nathalie Falk
- Animal Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Kristin Kessler
- Animal Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Sinja-Fee Schramm
- Animal Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Karsten Boldt
- Division of Experimental Ophthalmology and Medical Proteome Center, Center of Ophthalmology, University of Tübingen, 72074 Tübingen, Germany
| | - Elvir Becirovic
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Stylianos Michalakis
- Center for Integrated Protein Science Munich (CIPSM) at the Department of Pharmacy, Center for Drug Research, Ludwig-Maximilians-Universität München, 81377 Munich, Germany
| | - Hanna Regus-Leidig
- Animal Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
| | - Angelika A Noegel
- Institute of Biochemistry I, Medical Faculty, University Hospital, University of Cologne, 50931 Cologne, Germany
| | - Marius Ueffing
- Division of Experimental Ophthalmology and Medical Proteome Center, Center of Ophthalmology, University of Tübingen, 72074 Tübingen, Germany
| | - Christian T Thiel
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Ronald Roepman
- Department of Human Genetics, Radboud University Medical Center, Nijmegen 6525 GA, The Netherlands
| | | | - Andreas Gießl
- Animal Physiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, 91058 Erlangen, Germany
| |
Collapse
|
39
|
Brooks BP, Zein WM, Thompson AH, Mokhtarzadeh M, Doherty DA, Parisi M, Glass IA, Malicdan MC, Vilboux T, Vemulapalli M, Mullikin JC, Gahl WA, Gunay-Aygun M. Joubert Syndrome: Ophthalmological Findings in Correlation with Genotype and Hepatorenal Disease in 99 Patients Prospectively Evaluated at a Single Center. Ophthalmology 2018; 125:1937-1952. [PMID: 30055837 DOI: 10.1016/j.ophtha.2018.05.026] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 05/25/2018] [Accepted: 05/29/2018] [Indexed: 01/14/2023] Open
Abstract
PURPOSE Joubert syndrome (JS) is caused by mutations in >34 genes that encode proteins involved with primary (nonmotile) cilia and the cilium basal body. This study describes the varying ocular phenotypes in JS patients, with correlation to systemic findings and genotype. DESIGN Patients were systematically and prospectively examined at the National Institutes of Health (NIH) Clinical Center in the setting of a dedicated natural history clinical trial. PARTICIPANTS Ninety-nine patients with JS examined at a single center. METHODS All patients underwent genotyping for JS, followed by complete age-appropriate ophthalmic examinations at the NIH Clinical Center, including visual acuity (VA), fixation behavior, lid position, motility assessment, slit-lamp biomicroscopy, dilated fundus examination with an indirect ophthalmoscope, and retinoscopy. Color and fundus autofluorescence imaging, Optos wide-field photography (Dunfermline, Scotland, UK), and electroretinography (ERG) were performed when possible. MAIN OUTCOME MEASURES The VA (with longitudinal follow-up where possible), ptosis, extraocular muscle function, retinal and optic nerve status, and retinal function as measured by ERG. RESULTS Among patients with JS with quantifiable VA (68/99), values ranged from 0 logarithm of the minimum angle of resolution (logMAR) (Snellen 20/20) to 1.5 logMAR (Snellen 20/632). Strabismus (71/98), nystagmus (66/99), oculomotor apraxia (60/77), ptosis (30/98), coloboma (28/99), retinal degeneration (20/83), and optic nerve atrophy (8/86) were identified. CONCLUSIONS We recommend regular monitoring for ophthalmological manifestations of JS beginning soon after birth or diagnosis. We demonstrate delayed visual development and note that the amblyogenic time frame may last significantly longer in JS than is typical. In general, patients with coloboma were less likely to display retinal degeneration, and those with retinal degeneration did not have coloboma. Severe retinal degeneration that is early and aggressive is seen in disease caused by specific genes, such as CEP290- and AHI1-associated JS. Retinal degeneration in INPP5E-, MKS1-, and NPHP1-associated JS was generally milder. Finally, ptosis surgery can be helpful in a subset of patients with JS; decisions as to timing and benefit/risk ratio need to be made on an individual basis according to expert consultation.
Collapse
Affiliation(s)
- Brian P Brooks
- National Eye Institute, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland; National Human Genome Research Institute, Genetics and Molecular Biology Branch, Bethesda, Maryland; Office of the Clinical Director, National Eye Institute, National Institutes of Health, Bethesda, Maryland.
| | - Wadih M Zein
- National Eye Institute, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Amy H Thompson
- National Eye Institute, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland; Columbus Technologies & Services, Inc., Greenbelt, Maryland
| | - Maryam Mokhtarzadeh
- National Eye Institute, Ophthalmic Genetics and Visual Function Branch, National Eye Institute, National Institutes of Health, Bethesda, Maryland
| | - Daniel A Doherty
- Department of Pediatrics, University of Washington, Seattle, Washington; Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington
| | - Melissa Parisi
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Ian A Glass
- Department of Pediatrics, University of Washington, Seattle, Washington; Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, Washington
| | - May C Malicdan
- National Institutes of Health 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
| | - Thierry Vilboux
- National Human Genome Research Institute, Genetics and Molecular Biology Branch, Bethesda, Maryland; Inova Translational Medicine Institute, Falls Church, Virginia
| | - Meghana Vemulapalli
- National Institutes of Health Intramural Sequencing Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - James C Mullikin
- National Institutes of Health Intramural Sequencing Center, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - William A Gahl
- National Institutes of Health 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; Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland
| | - Meral Gunay-Aygun
- Medical Genetics Branch, 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
| |
Collapse
|
40
|
Brancati F, Camerota L, Colao E, Vega-Warner V, Zhao X, Zhang R, Bottillo I, Castori M, Caglioti A, Sangiuolo F, Novelli G, Perrotti N, Otto EA. Biallelic variants in the ciliary gene TMEM67 cause RHYNS syndrome. Eur J Hum Genet 2018; 26:1266-1271. [PMID: 29891882 DOI: 10.1038/s41431-018-0183-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 04/27/2018] [Accepted: 05/08/2018] [Indexed: 11/09/2022] Open
Abstract
A rare syndrome was first described in 1997 in a 17-year-old male patient presenting with Retinitis pigmentosa, HYpopituitarism, Nephronophthisis and Skeletal dysplasia (RHYNS). In the single reported familial case, two brothers were affected, arguing for X-linked or recessive mode of inheritance. Up to now, the underlying genetic basis of RHYNS syndrome remains unknown. Here we applied whole-exome sequencing in the originally described family with RHYNS to identify compound heterozygous variants in the ciliary gene TMEM67. Sanger sequencing confirmed a paternally inherited nonsense c.622A > T, p.(Arg208*) and a maternally inherited missense variant c.1289A > G, p.(Asp430Gly), which perturbs the correct splicing of exon 13. Overall, TMEM67 showed one of the widest clinical continuum observed in ciliopathies ranging from early lethality to adults with liver fibrosis. Our findings extend the spectrum of phenotypes/syndromes resulting from biallelic TMEM67 variants to now eight distinguishable clinical conditions including RHYNS syndrome.
Collapse
Affiliation(s)
- Francesco Brancati
- Department of Life, Health and Environmental Sciences, University of L'Aquila, L'Aquila, Italy. .,Laboratory of Molecular and Cell Biology, Istituto Dermopatico dell'Immacolata (IDI) IRCCS, Rome, Italy.
| | - Letizia Camerota
- Laboratory of Molecular and Cell Biology, Istituto Dermopatico dell'Immacolata (IDI) IRCCS, Rome, Italy
| | - Emma Colao
- Medical Genetics Unit, Mater Domini University Hospital, Catanzaro, Italy
| | - Virginia Vega-Warner
- Division of Nephrology, Department of Pediatrics and Communicable Diseases, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | - Xiangzhong Zhao
- Central Laboratory, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Ruixiao Zhang
- Department of Nephrology, The Affiliated Hospital of Qingdao University, Qingdao, China
| | - Irene Bottillo
- Division of Medical Genetics, Department of Molecular Medicine, Sapienza University, San Camillo-Forlanini Hospital, Rome, Italy
| | - Marco Castori
- Division of Medical Genetics, IRCCS Casa Sollievo della Sofferenza, San Giovanni Rotondo, Foggia, Italy
| | - Alfredo Caglioti
- Nephrology and Dialysis Unit, Mater Domini University Hospital, Catanzaro, Italy
| | - Federica Sangiuolo
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Giuseppe Novelli
- Department of Biomedicine and Prevention, University of Rome Tor Vergata, Rome, Italy
| | - Nicola Perrotti
- Department of Health Sciences, University of Catanzaro Magna Graecia, Catanzaro, Italy
| | - Edgar A Otto
- Division of Nephrology, Department of Internal Medicine, University of Michigan School of Medicine, Ann Arbor, Michigan, USA
| | | |
Collapse
|
41
|
Wheway G, Nazlamova L, Hancock JT. Signaling through the Primary Cilium. Front Cell Dev Biol 2018; 6:8. [PMID: 29473038 PMCID: PMC5809511 DOI: 10.3389/fcell.2018.00008] [Citation(s) in RCA: 291] [Impact Index Per Article: 48.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/23/2018] [Indexed: 12/13/2022] Open
Abstract
The presence of single, non-motile “primary” cilia on the surface of epithelial cells has been well described since the 1960s. However, for decades these organelles were believed to be vestigial, with no remaining function, having lost their motility. It wasn't until 2003, with the discovery that proteins responsible for transport along the primary cilium are essential for hedgehog signaling in mice, that the fundamental importance of primary cilia in signal transduction was realized. Little more than a decade later, it is now clear that the vast majority of signaling pathways in vertebrates function through the primary cilium. This has led to the adoption of the term “the cells's antenna” as a description for the primary cilium. Primary cilia are particularly important during development, playing fundamental roles in embryonic patterning and organogenesis, with a suite of inherited developmental disorders known as the “ciliopathies” resulting from mutations in genes encoding cilia proteins. This review summarizes our current understanding of the role of these fascinating organelles in a wide range of signaling pathways.
Collapse
Affiliation(s)
- Gabrielle Wheway
- Department of Applied Science, Faculty of Health and Applied Sciences, Centre for Research in Biosciences, University of the West of England, Bristol, United Kingdom
| | - Liliya Nazlamova
- Department of Applied Science, Faculty of Health and Applied Sciences, Centre for Research in Biosciences, University of the West of England, Bristol, United Kingdom
| | - John T Hancock
- Department of Applied Science, Faculty of Health and Applied Sciences, Centre for Research in Biosciences, University of the West of England, Bristol, United Kingdom
| |
Collapse
|
42
|
Arrigoni F, Romaniello R, Peruzzo D, De Luca A, Parazzini C, Valente EM, Borgatti R, Triulzi F. Anterior Mesencephalic Cap Dysplasia: Novel Brain Stem Malformative Features Associated with Joubert Syndrome. AJNR Am J Neuroradiol 2017; 38:2385-2390. [PMID: 28838911 DOI: 10.3174/ajnr.a5360] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Accepted: 06/30/2017] [Indexed: 11/07/2022]
Abstract
In Joubert syndrome, the "molar tooth" sign can be associated with several additional supra- and infratentorial malformations. Here we report on 3 subjects (2 siblings, 8-14 years of age) with Joubert syndrome, showing an abnormal thick bulging of the anterior profile of the mesencephalon causing a complete obliteration of the interpeduncular fossa. DTI revealed that the abnormal tissue consisted of an ectopic white matter tract with a laterolateral transverse orientation. Tractographic reconstructions support the hypothesis of impaired axonal guidance mechanisms responsible for the malformation. The 2 siblings were compound heterozygous for 2 missense variants in the TMEM67 gene, while no mutations in a panel of 120 ciliary genes were detected in the third patient. The name "anterior mesencephalic cap dysplasia," referring to the peculiar aspect of the mesencephalon on sagittal MR imaging, is proposed for this new malformative feature.
Collapse
Affiliation(s)
- F Arrigoni
- From the Neuroimaging Lab (F.A., D.P., A.D.L.)
| | - R Romaniello
- Neuropsychiatry and Neurorehabilitation Unit (R.R., R.B.), Scientific Institute Istituto Di Ricovero e Cura a Carattere Scientific Eugenio Medea, Bosisio Parini, Italy
| | - D Peruzzo
- From the Neuroimaging Lab (F.A., D.P., A.D.L.)
| | - A De Luca
- From the Neuroimaging Lab (F.A., D.P., A.D.L.)
- Department of Information Engineering (A.D.L.), University of Padova, Padova, Italy
| | - C Parazzini
- Department of Pediatric Radiology and Neuroradiology (C.P.), "V. Buzzi" Children's Hospital, Milan, Italy
| | - E M Valente
- Department of Molecular Medicine (E.M.V.), University of Pavia, Pavia, Italy
- Neurogenetics Unit (E.M.V.), Istituto Di Ricovero e Cura a Carattere Scientific Santa Lucia Foundation, Rome, Italy
| | - R Borgatti
- Neuropsychiatry and Neurorehabilitation Unit (R.R., R.B.), Scientific Institute Istituto Di Ricovero e Cura a Carattere Scientific Eugenio Medea, Bosisio Parini, Italy
| | - F Triulzi
- Department of Neuroradiology (F.T.), Scientific Institute Istituto Di Ricovero e Cura a Carattere Scientific Cà Granda Foundation-Ospedale Maggiore Policlinico, Milan, Italy
| |
Collapse
|
43
|
Lee SH, Nam TS, Li W, Kim JH, Yoon W, Choi YD, Kim KH, Cai H, Kim MJ, Kim C, Choy HE, Kim N, Chay KO, Kim MK, Choi SY. Functional validation of novel MKS3/TMEM67 mutations in COACH syndrome. Sci Rep 2017; 7:10222. [PMID: 28860541 PMCID: PMC5579020 DOI: 10.1038/s41598-017-10652-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2017] [Accepted: 08/10/2017] [Indexed: 12/18/2022] Open
Abstract
COACH syndrome is an autosomal recessive developmental disorder, a subtype of Joubert syndrome and related disorders, characterized by cerebellar vermis hypoplasia, oligophrenia, ataxia, coloboma, and hepatic fibrosis. Although mutations in TMEM67 (transmembrane protein 67)/MKS3 (Meckel-Gruber syndrome, type 3) were reported to cause COACH syndrome, this causality has not verified by functional studies. In a 20-year-old Korean man, we found cerebellar ataxia, isolated elevation in serum γ-glutamyl transpeptidase (γ-GTP) activity, oligophrenia, the molar tooth sign (MTS) in the brain MR images and congenital hepatic fibrosis (CHF). Two novel compound heterozygous mutations were found in TMEM67 in the patient: i) missense mutation (c.395 G > C and p.Gly132Ala) in exon 3, and ii) deletion in exon 26 (c.2758delT and p.Tyr920ThrfsX40). Western blotting showed that the p.Tyr920ThrfsX40 mutation accelerates turnover of the TMEM67 protein. Although wild-type human TMEM67 RNA rescued phenotypes of zebrafish embryos injected with anti-sense oligonucleotide morpholinos against tmem67, the two human TMEM67 RNAs individually harboring the two mutations did not. Finally, Wnt signaling, but not Hedgehog signaling, was suppressed in tmem67 morphants. To the best of our knowledge, this is the first report verifying the causality between COACH syndrome and TMEM67, which will further our understanding of molecular pathogenesis of the syndrome.
Collapse
Affiliation(s)
- So-Hyun Lee
- Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju, Republic of Korea.,Center for Creative Biomedical Scientists at Chonnam National University, Gwangju, Republic of Korea
| | - Tai-Seung Nam
- Department of Neurology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Wenting Li
- Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Jung Ha Kim
- Department of Pharmacology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Woong Yoon
- Department of Radiology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Yoo-Duk Choi
- Department of Pathology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Kun-Hee Kim
- Department of Microbiology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Hua Cai
- Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Min Jung Kim
- Department of Biological Sciences, Sookmyung Women's University, Seoul, Republic of Korea
| | - Changsoo Kim
- School of Biological Sciences and Technology, Chonnam National University, Gwangju, Republic of Korea
| | - Hyon E Choy
- Department of Microbiology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Nacksung Kim
- Department of Pharmacology, Chonnam National University Medical School, Gwangju, Republic of Korea
| | - Kee Oh Chay
- Department of Biochemistry, Chonnam National University Medical School, Gwangju, Republic of Korea.
| | - Myeong-Kyu Kim
- Department of Neurology, Chonnam National University Medical School, Gwangju, Republic of Korea.
| | - Seok-Yong Choi
- Department of Biomedical Sciences, Chonnam National University Medical School, Gwangju, Republic of Korea.
| |
Collapse
|
44
|
Vogel I, Ott P, Lildballe D, Hamilton-Dutoit S, Vilstrup H, Grønbæk H. Isolated congenital hepatic fibrosis associated with TMEM67 mutations: report of a new genotype-phenotype relationship. Clin Case Rep 2017; 5:1098-1102. [PMID: 28680603 PMCID: PMC5494401 DOI: 10.1002/ccr3.981] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 02/28/2017] [Accepted: 03/22/2017] [Indexed: 11/18/2022] Open
Abstract
We report an otherwise healthy 32‐year‐old man with portal hypertension, variceal bleeding, and congenital hepatic fibrosis with ductal plate malformation. Genetic screening identified two TMEM67 mutations. Biallelic TMEM67 mutations are known to cause Joubert/Meckel syndrome or nephronopthisis with hepatic fibrosis, but have never been found in isolated hepatic fibrosis.
Collapse
Affiliation(s)
- Ida Vogel
- Department of Clinical Genetics Aarhus University Hospital Aarhus Denmark
| | - Peter Ott
- Department of Hepatology and Gastroenterology V Aarhus University Hospital Aarhus Denmark
| | - Dorte Lildballe
- Department of Clinical Genetics Aarhus University Hospital Aarhus Denmark
| | | | - Hendrik Vilstrup
- Department of Hepatology and Gastroenterology V Aarhus University Hospital Aarhus Denmark
| | - Henning Grønbæk
- Department of Hepatology and Gastroenterology V Aarhus University Hospital Aarhus Denmark
| |
Collapse
|
45
|
Stayner C, Poole CA, McGlashan SR, Pilanthananond M, Brauning R, Markie D, Lett B, Slobbe L, Chae A, Johnstone AC, Jensen CG, McEwan JC, Dittmer K, Parker K, Wiles A, Blackburne W, Leichter A, Leask M, Pinnapureddy A, Jennings M, Horsfield JA, Walker RJ, Eccles MR. An ovine hepatorenal fibrocystic model of a Meckel-like syndrome associated with dysmorphic primary cilia and TMEM67 mutations. Sci Rep 2017; 7:1601. [PMID: 28487520 PMCID: PMC5431643 DOI: 10.1038/s41598-017-01519-4] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2016] [Accepted: 03/29/2017] [Indexed: 01/20/2023] Open
Abstract
Meckel syndrome (MKS) is an inherited autosomal recessive hepatorenal fibrocystic syndrome, caused by mutations in TMEM67, characterized by occipital encephalocoele, renal cysts, hepatic fibrosis, and polydactyly. Here we describe an ovine model of MKS, with kidney and liver abnormalities, without polydactyly or occipital encephalocoele. Homozygous missense p.(Ile681Asn; Ile687Ser) mutations identified in ovine TMEM67 were pathogenic in zebrafish phenotype rescue assays. Meckelin protein was expressed in affected and unaffected kidney epithelial cells by immunoblotting, and in primary cilia of lamb kidney cyst epithelial cells by immunofluorescence. In contrast to primary cilia of relatively consistent length and morphology in unaffected kidney cells, those of affected cyst-lining cells displayed a range of short and extremely long cilia, as well as abnormal morphologies, such as bulbous regions along the axoneme. Putative cilia fragments were also consistently located within the cyst luminal contents. The abnormal ciliary phenotype was further confirmed in cultured interstitial fibroblasts from affected kidneys. These primary cilia dysmorphologies and length control defects were significantly greater in affected cells compared to unaffected controls. In conclusion, we describe abnormalities involving primary cilia length and morphology in the first reported example of a large animal model of MKS, in which we have identified TMEM67 mutations.
Collapse
Affiliation(s)
- C Stayner
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - C A Poole
- Department of Medicine, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand.,150 Warren Street, Wanaka, 9305, New Zealand
| | - S R McGlashan
- Department of Anatomy and Medical Imaging, The University of Auckland 1142, Private Bag, 92019, Auckland, New Zealand
| | - M Pilanthananond
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - R Brauning
- AgResearch Invermay Agricultural Centre, Mosgiel, 9053, New Zealand
| | - D Markie
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - B Lett
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - L Slobbe
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - A Chae
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - A C Johnstone
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Tennant Drive, Palmerston North, 4472, New Zealand
| | - C G Jensen
- Department of Anatomy and Medical Imaging, The University of Auckland 1142, Private Bag, 92019, Auckland, New Zealand
| | - J C McEwan
- AgResearch Invermay Agricultural Centre, Mosgiel, 9053, New Zealand
| | - K Dittmer
- Institute of Veterinary, Animal and Biomedical Sciences, Massey University, Tennant Drive, Palmerston North, 4472, New Zealand
| | - K Parker
- Department of Medicine, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - A Wiles
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - W Blackburne
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - A Leichter
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - M Leask
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - A Pinnapureddy
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - M Jennings
- Department of Medicine, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - J A Horsfield
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - R J Walker
- Department of Medicine, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand
| | - M R Eccles
- Department of Pathology, Dunedin School of Medicine, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
| |
Collapse
|
46
|
Gonçalves J, Pelletier L. The Ciliary Transition Zone: Finding the Pieces and Assembling the Gate. Mol Cells 2017; 40:243-253. [PMID: 28401750 PMCID: PMC5424270 DOI: 10.14348/molcells.2017.0054] [Citation(s) in RCA: 127] [Impact Index Per Article: 18.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Accepted: 04/05/2017] [Indexed: 12/23/2022] Open
Abstract
Eukaryotic cilia are organelles that project from the surface of cells to fulfill motility and sensory functions. In vertebrates, the functions of both motile and immotile cilia are critical for embryonic development and adult tissue homeostasis. Importantly, a multitude of human diseases is caused by abnormal cilia biogenesis and functions which rely on the compartmentalization of the cilium and the maintenance of its protein composition. The transition zone (TZ) is a specialized ciliary domain present at the base of the cilium and is part of a gate that controls protein entry and exit from this organelle. The relevance of the TZ is highlighted by the fact that several of its components are coded by ciliopathy genes. Here we review recent developments in the study of TZ proteomes, the mapping of individual components to the TZ structure and the establishment of the TZ as a lipid gate.
Collapse
Affiliation(s)
- João Gonçalves
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5,
Canada
| | - Laurence Pelletier
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, 600 University Avenue, Toronto, ON M5G 1X5,
Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8,
Canada
| |
Collapse
|
47
|
Goetz SC, Bangs F, Barrington CL, Katsanis N, Anderson KV. The Meckel syndrome- associated protein MKS1 functionally interacts with components of the BBSome and IFT complexes to mediate ciliary trafficking and hedgehog signaling. PLoS One 2017; 12:e0173399. [PMID: 28291807 PMCID: PMC5349470 DOI: 10.1371/journal.pone.0173399] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 02/20/2017] [Indexed: 12/04/2022] Open
Abstract
The importance of primary cilia in human health is underscored by the link between ciliary dysfunction and a group of primarily recessive genetic disorders with overlapping clinical features, now known as ciliopathies. Many of the proteins encoded by ciliopathy-associated genes are components of a handful of multi-protein complexes important for the transport of cargo to the basal body and/or into the cilium. A key question is whether different complexes cooperate in cilia formation, and whether they participate in cilium assembly in conjunction with intraflagellar transport (IFT) proteins. To examine how ciliopathy protein complexes might function together, we have analyzed double mutants of an allele of the Meckel syndrome (MKS) complex protein MKS1 and the BBSome protein BBS4. We find that Mks1; Bbs4 double mutant mouse embryos exhibit exacerbated defects in Hedgehog (Hh) dependent patterning compared to either single mutant, and die by E14.5. Cells from double mutant embryos exhibit a defect in the trafficking of ARL13B, a ciliary membrane protein, resulting in disrupted ciliary structure and signaling. We also examined the relationship between the MKS complex and IFT proteins by analyzing double mutant between Mks1 and a hypomorphic allele of the IFTB component Ift172. Despite each single mutant surviving until around birth, Mks1; Ift172avc1 double mutants die at mid-gestation, and exhibit a dramatic failure of cilia formation. We also find that Mks1 interacts genetically with an allele of Dync2h1, the IFT retrograde motor. Thus, we have demonstrated that the MKS transition zone complex cooperates with the BBSome to mediate trafficking of specific trans-membrane receptors to the cilium. Moreover, the genetic interaction of Mks1 with components of IFT machinery suggests that the transition zone complex facilitates IFT to promote cilium assembly and structure.
Collapse
Affiliation(s)
- Sarah C. Goetz
- Program in Developmental Biology, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Ave. New York, United States of America
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, United States of America
| | - Fiona Bangs
- Program in Developmental Biology, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Ave. New York, United States of America
| | - Chloe L. Barrington
- Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC, United States of America
| | - Nicholas Katsanis
- Department of Cell Biology and Center for Human Disease Modeling, Duke University Medical Center, Durham, NC, United States of America
| | - Kathryn V. Anderson
- Program in Developmental Biology, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, 1275 York Ave. New York, United States of America
| |
Collapse
|
48
|
Du E, Zhang C, Qin Z, Yang K, Li C, Wang A, Zhang Z, Xu Y. Low expression of TMEM67 is a critical predictor of poor prognosis in human urothelial carcinoma of the bladder. Urol Oncol 2017; 35:152.e7-152.e12. [PMID: 28161324 DOI: 10.1016/j.urolonc.2016.10.014] [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: 07/28/2016] [Revised: 10/15/2016] [Accepted: 10/19/2016] [Indexed: 11/29/2022]
Abstract
OBJECTIVES The aim of the study was to evaluate the expression of TMEM67 in urothelial carcinoma of the bladder (UCB) tissues and to determine the potential relevance between the expression of TMEM67 and prognosis of UCB. MATERIAL AND METHODS In this study, the expression of TMEM67 mRNA was performed by quantitative real-time PCR in 80 UCB and 54 noncancerous tissues. The expression of TMEM67 protein was identified by immunohistochemistry and western blotting. Chi-square test was conducted to verify the relevance between the expression of TMEM67 and clinical parameters. Kaplan-Meier survival analysis was demonstrated between high or low expression level of TMEM67 mRNA and recurrence-free survival probability. Cox regression analysis was conducted to evaluate the relevance between the expression of TMEM67 and the prognosis in UCB. RESULTS Low expression of TMEM67 mRNA and protein was detected in most of UCB tissues using quantitative real-time polymerase chain reaction and western blotting, compared with noncancerous tissues. Low expressions of TMEM67 were associated with TNM stage, grade, and lymph node metastasis (P<0.05). Kaplan-Meier analysis showed that the low expression of TMEM67 mRNA had significantly shorter recurrence-free survival probability (P = 0.018). Cox regression analysis confirmed that low expression of TMEM67 mRNA predicted poor prognosis of patients with UCB (HR = 2.950, P = 0.029, 95% CI: 1.116-7.796). CONCLUSIONS TMEM67 expression is low in UCB tissues, and the TMEM67 low expression predicted poor prognosis of patients with UCB.
Collapse
Affiliation(s)
- E Du
- Tianjin Institute of Urology, The 2nd Hospital of Tianjin Medical University, Tianjin, China
| | - Changwen Zhang
- Tianjin Institute of Urology, The 2nd Hospital of Tianjin Medical University, Tianjin, China
| | - Zhenbang Qin
- Tianjin Institute of Urology, The 2nd Hospital of Tianjin Medical University, Tianjin, China
| | - Kuo Yang
- Tianjin Institute of Urology, The 2nd Hospital of Tianjin Medical University, Tianjin, China
| | - Changying Li
- Tianjin Institute of Urology, The 2nd Hospital of Tianjin Medical University, Tianjin, China
| | - Aixiang Wang
- Tianjin Institute of Urology, The 2nd Hospital of Tianjin Medical University, Tianjin, China
| | - Zhihong Zhang
- Tianjin Institute of Urology, The 2nd Hospital of Tianjin Medical University, Tianjin, China.
| | - Yong Xu
- Tianjin Institute of Urology, The 2nd Hospital of Tianjin Medical University, Tianjin, China.
| |
Collapse
|
49
|
Malicki JJ, Johnson CA. The Cilium: Cellular Antenna and Central Processing Unit. Trends Cell Biol 2017; 27:126-140. [PMID: 27634431 PMCID: PMC5278183 DOI: 10.1016/j.tcb.2016.08.002] [Citation(s) in RCA: 240] [Impact Index Per Article: 34.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2016] [Revised: 07/14/2016] [Accepted: 08/04/2016] [Indexed: 12/14/2022]
Abstract
Cilia mediate an astonishing diversity of processes. Recent advances provide unexpected insights into the regulatory mechanisms of cilium formation, and reveal diverse regulatory inputs that are related to the cell cycle, cytoskeleton, proteostasis, and cilia-mediated signaling itself. Ciliogenesis and cilia maintenance are regulated by reciprocal antagonistic or synergistic influences, often acting in parallel to each other. By receiving parallel inputs, cilia appear to integrate multiple signals into specific outputs and may have functions similar to logic gates of digital systems. Some combinations of input signals appear to impose higher hierarchical control related to the cell cycle. An integrated view of these regulatory inputs will be necessary to understand ciliogenesis and its wider relevance to human biology.
Collapse
Affiliation(s)
- Jarema J Malicki
- Bateson Centre and Department of Biomedical Science, University of Sheffield, Western Bank Sheffield, S10 2TN, UK.
| | - Colin A Johnson
- Wellcome Trust Brenner Building, Leeds Institute of Biomedical and Clinical Sciences, University of Leeds, Beckett Street, Leeds LS9 7TF, UK.
| |
Collapse
|
50
|
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.
Collapse
|