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Dougherty GW, Ostrowski LE, Nöthe-Menchen T, Raidt J, Schramm A, Olbrich H, Yin W, Sears PR, Dang H, Smith AJ, Beule AG, Hjeij R, Rutjes N, Haarman EG, Maas SM, Ferkol TW, Noone PG, Olivier KN, Bracht DC, Barbry P, Zaragosi LE, Fierville M, Kliesch S, Wohlgemuth K, König J, George S, Loges NT, Ceppe A, Markovetz MR, Luo H, Guo T, Rizk H, Eldesoky T, Dahlke K, Boldt K, Ueffing M, Hill DB, Pang YP, Knowles MR, Zariwala MA, Omran H. Recessively Inherited Deficiency of Secreted WFDC2 (HE4) Causes Nasal Polyposis and Bronchiectasis. Am J Respir Crit Care Med 2024. [PMID: 38626355 DOI: 10.1164/rccm.202308-1370oc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 04/16/2024] [Indexed: 04/18/2024] Open
Abstract
RATIONALE Bronchiectasis is a pathological dilatation of the bronchi in the respiratory airways associated with environmental or genetic causes (e.g., cystic fibrosis, primary ciliary dyskinesia and primary immunodeficiency disorders), but most cases remain idiopathic. OBJECTIVES To identify novel genetic defects in unsolved cases of bronchiectasis presenting with severe rhinosinusitis, nasal polyposis, and pulmonary Pseudomonas aeruginosa infection. METHODS DNA was analyzed by next-generation or targeted Sanger sequencing. RNA was analyzed by quantitative PCR and single-cell RNA sequencing. Patient-derived, cells, cell cultures and secretions (mucus, saliva, seminal fluid) were analyzed by Western blotting and immunofluorescence microscopy, and mucociliary activity was measured. Blood serum was analyzed by electrochemiluminescence immunoassay. Protein structure and proteomic analyses were used to assess the impact of a disease-causing founder variant. MEASUREMENTS AND MAIN RESULTS We identified bi-allelic pathogenic variants in WFDC2 in 11 individuals from 10 unrelated families originating from the United States, Europe, Asia, and Africa. Expression of WFDC2 was detected predominantly in secretory cells of control airway epithelium and also in submucosal glands. We demonstrate that WFDC2 is below the limit of detection in blood serum and hardly detectable in samples of saliva, seminal fluid, and airway surface liquid from WFDC2-deficient individuals. Computer simulations and deglycosylation assays indicate that the disease-causing founder variant p.Cys49Arg structurally hampers glycosylation and thus secretion of mature WFDC2. CONCLUSIONS WFDC2 dysfunction defines a novel molecular etiology of bronchiectasis characterized by the deficiency of a secreted component of the airways. A commercially available blood test combined with genetic testing allows its diagnosis. This article is open access and distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).
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Affiliation(s)
| | - Lawrence E Ostrowski
- Universtiy of North Carolina at Chapel Hill, Marsico Lung Institute/ Cystic Fibrosis Center, Chapel Hill, North Carolina, United States
- United States
| | | | - Johanna Raidt
- University Hospital Muenster, Pediatrics, Muenster, Germany
| | - Andre Schramm
- University Hospital Muenster, General Pediatrics, Muenster, Germany
| | - Heike Olbrich
- University Hospital Muenster, General Pediatrics, Muenster, Germany
| | - Weining Yin
- University of North Carolina at Chapel Hill, 2331, Marsico Lung Institute/Cystic Fibrosis Research Center, Chapel Hill, North Carolina, United States
| | - Patrick R Sears
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Hong Dang
- UNC, Marsico Lung Institute, Chapel Hill, North Carolina, United States
| | - Amanda J Smith
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Achim G Beule
- University Clinic Münster, Dept. of ENT, Münster, Germany
| | - Rim Hjeij
- University Hospital Muenster, Pediatrics, Muenster, Germany
| | - Niels Rutjes
- Amsterdam UMC, Emma Children's Hospital, Department of Pediatric Pulmonology & Allergy, Amsterdam, Netherlands
| | - Eric G Haarman
- Amsterdam UMC, 522567, Department of Pediatric Pulmonology, Emma Children's Hospital, Amsterdam, Noord-Holland, Netherlands
| | - Saskia M Maas
- Amsterdam UMC, Emma Children's Hospital, Department of Pediatric Pulmonology & Allergy, Amsterdam, Netherlands
| | - Thomas W Ferkol
- The University of North Carolina at Chapel Hill, 2331, Chapel Hill, North Carolina, United States
| | | | - Kenneth N Olivier
- The University of North Carolina at Chapel Hill, 2331, Medicine, Chapel Hill, North Carolina, United States
| | - Diana C Bracht
- University Children's Hospital Muenster, Department of General Pediatrics, Muenster, Germany
| | - Pascal Barbry
- Université Côte d'Azur, Institut de Pharmacologie Moléculaire et Cellulaire, Sophia Antipolis, France
- CNRS, 27051, Institut de Pharmacologie Moléculaire et Cellulaire, Sophia Antipolis, France
| | - Laure-Emmanuelle Zaragosi
- Université Côte d'Azur, 439710, Institut de Pharmacologie Moléculaire et Cellulaire, Sophia Antipolis, Provence-Alpes-Côte d'Azur, France
- CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, Sophia Antipolis, France
| | - Morgane Fierville
- Université Côte d'Azur and CNRS, 3IA Côte d'Azur & Institut de Pharmacologie Moléculaire et Cellulaire, Sophia Antipolis, France
| | - Sabine Kliesch
- Centre of Reproductive Medicine and Andrology, University Hospital Muenster, Department of Clinical and Surgical Andrology, Muenster, Germany
| | - Kai Wohlgemuth
- University Hospital Muenster, Department of General Pediatrics, Muenster, Germany
| | - Julia König
- University Children´s Hospital Muenster, Department of General Pediatrics, Muenster, Germany
| | - Sebastian George
- University Hospital Muenster, Department of General Pediatrics, Muenster, Germany
| | - Niki T Loges
- University Hospital Muenster, Pediatrics, Muenster, Germany
| | - Agathe Ceppe
- University of North Carolina at Chapel Hill, 2331, Chapel Hill, North Carolina, United States
| | - Matthew R Markovetz
- University of North Carolina at Chapel Hill, Marsico Lung Institute, Chapel Hill, North Carolina, United States
| | - Hong Luo
- Second Xiangya Hospital, 70566, Respiratory and Critical Care Medicine, Changsha, China
| | - Ting Guo
- Second Xiangya Hospital, Central South University, Department of Pulmonary and Critical Care Medicine, Changsha, Hunan, China
| | - Hoda Rizk
- Faculty of Medicine, University of Mansoura, Department of Pediatrics, Mansoura, Egypt
| | - Tarek Eldesoky
- Faculty of Medicine, University of Mansoura, Department of Pediatrics, Mansoura, Egypt
| | - Katrin Dahlke
- Institute for Ophthalmic Research and Core Facility for Medical Proteomics, Eberhard Karls University Tübingen, Tuebingen, Germany
| | - Karsten Boldt
- Institute for Ophthalmic Research and Core Facility for Medical Proteomics, Eberhard Karls University Tübingen, Tuebingen, Germany
| | - Marius Ueffing
- Institute for Ophthalmic Research and Core Facility for Medical Proteomics, Eberhard Karls University Tübingen, Tuebingen, Germany
| | - David B Hill
- University of North Carolina, Marsico Lung Institute, Chapel Hill, North Carolina, United States
| | - Yuan-Ping Pang
- Mayo Clinic, Department of Molecular Pharmacology and Experimental Therapeutics, Rochester, Minnesota, United States
| | - Michael R Knowles
- University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States
| | - Maimoona A Zariwala
- UNC School of Medicine, Pathology/Lab Medicine, Chapel Hill, North Carolina, United States
| | - Heymut Omran
- University Hospital Münster, General Pediatrics, Münster, Germany;
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2
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Sears PR, Ostrowski LE. Mucociliary Transport Device Construction and Application to Study Mucociliary Clearance. Methods Mol Biol 2024; 2725:263-276. [PMID: 37856031 DOI: 10.1007/978-1-0716-3507-0_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2023]
Abstract
Well-differentiated air-liquid interface cultures of airway epithelial cells produce and secrete mucus and have abundant cilia that beat in the apical fluid. In cultures, this ciliary beating is not well coordinated or occurs in small focal areas so the resulting mucociliary transport (MCT) is only linear over short distances. We present a method which induces ciliated cells in cultures to align during growth. The cells align along the axis of a defined circular track, thus producing a well-coordinated rotational transport which is effectively linear on length scales of ciliated cells. These modified inserts - referred to as mucociliary transport devices (MCTDs) - are simple to prepare and result reproducibly in a high percentage of cultures demonstrating complete circular transport (CCT).
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Affiliation(s)
- Patrick R Sears
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, USA
| | - Lawrence E Ostrowski
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, USA.
- Department of Pediatrics, University of North Carolina, Chapel Hill, NC, USA.
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3
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Smith AJ, Bustamante-Marin XM, Yin W, Sears PR, Herring LE, Dicheva NN, López-Giráldez F, Mane S, Tarran R, Leigh MW, Knowles MR, Zariwala MA, Ostrowski LE. The role of SPAG1 in the assembly of axonemal dyneins in human airway epithelia. J Cell Sci 2022; 135:jcs259512. [PMID: 35178554 PMCID: PMC8995097 DOI: 10.1242/jcs.259512] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 02/14/2022] [Indexed: 11/20/2022] Open
Abstract
Mutations in SPAG1, a dynein axonemal assembly factor (DNAAF) that facilitates the assembly of dynein arms in the cytoplasm before their transport into the cilium, result in primary ciliary dyskinesia (PCD), a genetically heterogenous disorder characterized by chronic oto-sino-pulmonary disease, infertility and laterality defects. To further elucidate the role of SPAG1 in dynein assembly, we examined its expression, interactions and ciliary defects in control and PCD human airway epithelia. Immunoprecipitations showed that SPAG1 interacts with multiple DNAAFs, dynein chains and canonical components of the R2TP complex. Protein levels of dynein heavy chains (DHCs) and interactions between DHCs and dynein intermediate chains (DICs) were reduced in SPAG1 mutants. We also identified a previously uncharacterized 60 kDa SPAG1 isoform, through examination of PCD subjects with an atypical ultrastructural defect for SPAG1 variants, that can partially compensate for the absence of full-length SPAG1 to assemble a reduced number of outer dynein arms. In summary, our data show that SPAG1 is necessary for axonemal dynein arm assembly by scaffolding R2TP-like complexes composed of several DNAAFs that facilitate the folding and/or binding of the DHCs to the DIC complex.
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Affiliation(s)
- Amanda J. Smith
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Ximena M. Bustamante-Marin
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Weining Yin
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Patrick R. Sears
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Laura E. Herring
- University of North Carolina Proteomics Core Facility, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Nedyalka N. Dicheva
- University of North Carolina Proteomics Core Facility, Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | | | - Shrikant Mane
- Yale Center for Genome Analysis, Yale University, New Haven, CT 06520, USA
| | - Robert Tarran
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Margaret W. Leigh
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Michael R. Knowles
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Maimoona A. Zariwala
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Lawrence E. Ostrowski
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
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Ostrowski LE, Yin W, Smith AJ, Sears PR, Bustamante-Marin XM, Dang H, Hildebrandt F, Daniels LA, Capps NA, Sullivan KM, Leigh MW, Zariwala MA, Knowles MR. Expression of a Truncated Form of ODAD1 Associated with an Unusually Mild Primary Ciliary Dyskinesia Phenotype. Int J Mol Sci 2022; 23:ijms23031753. [PMID: 35163670 PMCID: PMC8835943 DOI: 10.3390/ijms23031753] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/19/2022] [Accepted: 01/30/2022] [Indexed: 11/25/2022] Open
Abstract
Primary ciliary dyskinesia (PCD) is a rare lung disease caused by mutations that impair the function of motile cilia, resulting in chronic upper and lower respiratory disease, reduced fertility, and a high prevalence of situs abnormalities. The disease is genetically and phenotypically heterogeneous, with causative mutations in > 50 genes identified, and clinical phenotypes ranging from mild to severe. Absence of ODAD1 (CCDC114), a component of the outer dynein arm docking complex, results in a failure to assemble outer dynein arms (ODAs), mostly immotile cilia, and a typical PCD phenotype. We identified a female (now 34 years old) with an unusually mild clinical phenotype who has a homozygous non-canonical splice mutation (c.1502+5G>A) in ODAD1. To investigate the mechanism for the unusual phenotype, we performed molecular and functional studies of cultured nasal epithelial cells. We demonstrate that this splice mutation results in the expression of a truncated protein that is attached to the axoneme, indicating that the mutant protein retains partial function. This allows for the assembly of some ODAs and a significant level of ciliary activity that may result in the atypically mild clinical phenotype. The results also suggest that partial restoration of ciliary function by therapeutic agents could lead to significant improvement of disease symptoms.
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Affiliation(s)
- Lawrence E. Ostrowski
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (W.Y.); (A.J.S.); (P.R.S.); (X.M.B.-M.); (H.D.); (L.A.D.); (N.A.C.); (K.M.S.); (M.W.L.); (M.A.Z.)
- Department of Pediatrics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Correspondence: (L.E.O.); (M.R.K.)
| | - Weining Yin
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (W.Y.); (A.J.S.); (P.R.S.); (X.M.B.-M.); (H.D.); (L.A.D.); (N.A.C.); (K.M.S.); (M.W.L.); (M.A.Z.)
| | - Amanda J. Smith
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (W.Y.); (A.J.S.); (P.R.S.); (X.M.B.-M.); (H.D.); (L.A.D.); (N.A.C.); (K.M.S.); (M.W.L.); (M.A.Z.)
| | - Patrick R. Sears
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (W.Y.); (A.J.S.); (P.R.S.); (X.M.B.-M.); (H.D.); (L.A.D.); (N.A.C.); (K.M.S.); (M.W.L.); (M.A.Z.)
| | - Ximena M. Bustamante-Marin
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (W.Y.); (A.J.S.); (P.R.S.); (X.M.B.-M.); (H.D.); (L.A.D.); (N.A.C.); (K.M.S.); (M.W.L.); (M.A.Z.)
| | - Hong Dang
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (W.Y.); (A.J.S.); (P.R.S.); (X.M.B.-M.); (H.D.); (L.A.D.); (N.A.C.); (K.M.S.); (M.W.L.); (M.A.Z.)
| | - Friedhelm Hildebrandt
- Department of Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02113, USA;
| | - Leigh Anne Daniels
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (W.Y.); (A.J.S.); (P.R.S.); (X.M.B.-M.); (H.D.); (L.A.D.); (N.A.C.); (K.M.S.); (M.W.L.); (M.A.Z.)
| | - Nicole A. Capps
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (W.Y.); (A.J.S.); (P.R.S.); (X.M.B.-M.); (H.D.); (L.A.D.); (N.A.C.); (K.M.S.); (M.W.L.); (M.A.Z.)
| | - Kelli M. Sullivan
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (W.Y.); (A.J.S.); (P.R.S.); (X.M.B.-M.); (H.D.); (L.A.D.); (N.A.C.); (K.M.S.); (M.W.L.); (M.A.Z.)
| | - Margaret W. Leigh
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (W.Y.); (A.J.S.); (P.R.S.); (X.M.B.-M.); (H.D.); (L.A.D.); (N.A.C.); (K.M.S.); (M.W.L.); (M.A.Z.)
- Department of Pediatrics, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Maimoona A. Zariwala
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (W.Y.); (A.J.S.); (P.R.S.); (X.M.B.-M.); (H.D.); (L.A.D.); (N.A.C.); (K.M.S.); (M.W.L.); (M.A.Z.)
- Department of Pathology and Laboratory Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Michael R. Knowles
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA; (W.Y.); (A.J.S.); (P.R.S.); (X.M.B.-M.); (H.D.); (L.A.D.); (N.A.C.); (K.M.S.); (M.W.L.); (M.A.Z.)
- Department of Medicine, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
- Correspondence: (L.E.O.); (M.R.K.)
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Kato T, Mikami Y, Sun L, Rogers TD, Grubb BR, Morrison CB, Ehre C, Sears PR, Ostrowski LE, Randell SH, Boucher RC. Reuse of Cell Culture Inserts for In Vitro Human Primary Airway Epithelial Cell Studies. Am J Respir Cell Mol Biol 2021; 64:760-764. [PMID: 33788673 PMCID: PMC8456889 DOI: 10.1165/rcmb.2021-0033le] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Affiliation(s)
- Takafumi Kato
- University of North CarolinaChapel Hill, North Carolina
| | - Yu Mikami
- University of North CarolinaChapel Hill, North Carolina
| | - Ling Sun
- University of North CarolinaChapel Hill, North Carolina
| | | | | | | | - Camille Ehre
- University of North CarolinaChapel Hill, North Carolina
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Zhao Y, Pinskey J, Lin J, Yin W, Sears PR, Daniels LA, Zariwala MA, Knowles MR, Ostrowski LE, Nicastro D. Structural insights into the cause of human RSPH4A primary ciliary dyskinesia. Mol Biol Cell 2021; 32:1202-1209. [PMID: 33852348 PMCID: PMC8351563 DOI: 10.1091/mbc.e20-12-0806] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 03/25/2021] [Accepted: 04/06/2021] [Indexed: 11/30/2022] Open
Abstract
Cilia and flagella are evolutionarily conserved eukaryotic organelles involved in cell motility and signaling. In humans, mutations in Radial Spoke Head Component 4A (RSPH4A) can lead to primary ciliary dyskinesia (PCD), a life-shortening disease characterized by chronic respiratory tract infections, abnormal organ positioning, and infertility. Despite its importance for human health, the location of RSPH4A in human cilia has not been resolved, and the structural basis of RSPH4A-/- PCD remains elusive. Here, we present the native three-dimensional structure of RSPH4A-/- human respiratory cilia using samples collected noninvasively from a PCD patient. Using cryo-electron tomography (cryo-ET) and subtomogram averaging, we compared the structures of control and RSPH4A-/- cilia, revealing primary defects in two of the three radial spokes (RSs) within the axonemal repeat and secondary (heterogeneous) defects in the central pair complex. Similar to RSPH1-/- cilia, the radial spoke heads of RS1 and RS2, but not RS3, were missing in RSPH4A-/- cilia. However, RSPH4A-/- cilia also exhibited defects within the arch domains adjacent to the RS1 and RS2 heads, which were not observed with RSPH1 loss. Our results provide insight into the underlying structural basis for RSPH4A-/- PCD and highlight the benefits of applying cryo-ET directly to patient samples for molecular structure determination.
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Affiliation(s)
- Yanhe Zhao
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Justine Pinskey
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Jianfeng Lin
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - Weining Yin
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC 27599
| | - Patrick R Sears
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC 27599
| | - Leigh A Daniels
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC 27599
- Department of Medicine
| | - Maimoona A Zariwala
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC 27599
- Department of Pathology and Laboratory Medicine, and
| | - Michael R Knowles
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC 27599
- Department of Medicine
| | - Lawrence E Ostrowski
- Marsico Lung Institute, University of North Carolina, Chapel Hill, NC 27599
- Department of Pediatrics, University of North Carolina School of Medicine, Chapel Hill, NC 27599
| | - Daniela Nicastro
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390
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Sears PR, Bustamante-Marin XM, Gong H, Markovetz MR, Superfine R, Hill DB, Ostrowski LE. Induction of ciliary orientation by matrix patterning and characterization of mucociliary transport. Biophys J 2021; 120:1387-1395. [PMID: 33705757 PMCID: PMC8105732 DOI: 10.1016/j.bpj.2021.01.041] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/13/2021] [Accepted: 01/20/2021] [Indexed: 11/17/2022] Open
Abstract
Impaired mucociliary clearance (MCC) is a key feature of many airway diseases, including asthma, bronchiectasis, chronic obstructive pulmonary disease, cystic fibrosis, and primary ciliary dyskinesia. To improve MCC and develop new treatments for these diseases requires a thorough understanding of how mucus concentration, mucus composition, and ciliary activity affect MCC, and how different therapeutics impact this process. Although differentiated cultures of human airway epithelial cells are useful for investigations of MCC, the extent of ciliary coordination in these cultures varies, and the mechanisms controlling ciliary orientation are not completely understood. By introducing a pattern of ridges and grooves into the underlying collagen substrate, we demonstrate for the first time, to our knowledge, that changes in the extracellular matrix can induce ciliary alignment. Remarkably, 90% of human airway epithelial cultures achieved continuous directional mucociliary transport (MCT) when grown on the patterned substrate. These cultures maintain transport for months, allowing carefully controlled investigations of MCC over a wide range of normal and pathological conditions. To characterize the system, we measured the transport of bovine submaxillary gland mucin (BSM) under several conditions. Transport of 5% BSM was significantly reduced compared with that of 2% BSM, and treatment of 5% BSM with the reducing agent tris(2-carboxyethyl)phosphine (TCEP) reduced viscosity and increased the rate of MCT by approximately twofold. Addition of a small amount of high-molecular-weight DNA increased mucus viscosity and reduced MCT by ∼75%, demonstrating that the composition of mucus, as well as the concentration, can have significant effects on MCT. Our results demonstrate that a simple patterning of the collagen substrate results in highly coordinated ciliated cultures that develop directional MCT, and can be used to investigate the mechanisms controlling the regulation of ciliary orientation. Furthermore, the results demonstrate that this method provides an improved system for studying the effects of mucus composition and therapeutic agents on MCC.
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Affiliation(s)
- Patrick R Sears
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina
| | | | - Henry Gong
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina
| | - Matthew R Markovetz
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina
| | - Richard Superfine
- Department of Applied Physical Sciences, University of North Carolina, Chapel Hill, North Carolina
| | - David B Hill
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina; Department of Physics and Astronomy, University of North Carolina, Chapel Hill, North Carolina
| | - Lawrence E Ostrowski
- Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina; Department of Pediatrics, University of North Carolina, Chapel Hill, North Carolina.
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Bustamante-Marin XM, Horani A, Stoyanova M, Charng WL, Bottier M, Sears PR, Yin WN, Daniels LA, Bowen H, Conrad DF, Knowles MR, Ostrowski LE, Zariwala MA, Dutcher SK. Mutation of CFAP57, a protein required for the asymmetric targeting of a subset of inner dynein arms in Chlamydomonas, causes primary ciliary dyskinesia. PLoS Genet 2020; 16:e1008691. [PMID: 32764743 PMCID: PMC7444499 DOI: 10.1371/journal.pgen.1008691] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 08/19/2020] [Accepted: 02/22/2020] [Indexed: 01/10/2023] Open
Abstract
Primary ciliary dyskinesia (PCD) is characterized by chronic airway disease, reduced fertility, and randomization of the left/right body axis. It is caused by defects of motile cilia and sperm flagella. We screened a cohort of affected individuals that lack an obvious axonemal defect for pathogenic variants using whole exome capture, next generation sequencing, and bioinformatic analysis assuming an autosomal recessive trait. We identified one subject with an apparently homozygous nonsense variant [(c.1762C>T), p.(Arg588*)] in the uncharacterized CFAP57 gene. Interestingly, the variant results in the skipping of exon 11 (58 amino acids), which may be due to disruption of an exonic splicing enhancer. In normal human nasal epithelial cells, CFAP57 localizes throughout the ciliary axoneme. Nasal cells from the PCD patient express a shorter, mutant version of CFAP57 and the protein is not incorporated into the axoneme. The missing 58 amino acids include portions of WD repeats that may be important for loading onto the intraflagellar transport (IFT) complexes for transport or docking onto the axoneme. A reduced beat frequency and an alteration in ciliary waveform was observed. Knockdown of CFAP57 in human tracheobronchial epithelial cells (hTECs) recapitulates these findings. Phylogenetic analysis showed that CFAP57 is highly conserved in organisms that assemble motile cilia. CFAP57 is allelic with the BOP2/IDA8/FAP57 gene identified previously in Chlamydomonas reinhardtii. Two independent, insertional fap57 Chlamydomonas mutant strains show reduced swimming velocity and altered waveforms. Tandem mass tag (TMT) mass spectroscopy shows that FAP57 is missing, and the "g" inner dyneins (DHC7 and DHC3) and the "d" inner dynein (DHC2) are reduced, but the FAP57 paralog FBB7 is increased. Together, our data identify a homozygous variant in CFAP57 that causes PCD that is likely due to a defect in the inner dynein arm assembly process.
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Affiliation(s)
- Ximena M. Bustamante-Marin
- Department of Medicine, Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Amjad Horani
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Mihaela Stoyanova
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Wu-Lin Charng
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Department of Neurology, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Mathieu Bottier
- Department of Mechanical Engineering, Washington University, St. Louis, Missouri, United States of America
| | - Patrick R. Sears
- Department of Medicine, Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Wei-Ning Yin
- Department of Medicine, Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Leigh Anne Daniels
- Department of Medicine, Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Hailey Bowen
- Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri, United States of America
| | - Donald F. Conrad
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
- Division of Genetics, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, United States of America
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, Oregon, United States of America
| | - Michael R. Knowles
- Department of Medicine, Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Lawrence E. Ostrowski
- Department of Medicine, Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Maimoona A. Zariwala
- Department of Pathology and Laboratory Medicine and the Marsico Lung Institute, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Susan K. Dutcher
- Department of Genetics, Washington University School of Medicine, St. Louis, Missouri, United States of America
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9
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Yin W, Livraghi-Butrico A, Sears PR, Rogers TD, Burns KA, Grubb BR, Ostrowski LE. Mice with a Deletion of Rsph1 Exhibit a Low Level of Mucociliary Clearance and Develop a Primary Ciliary Dyskinesia Phenotype. Am J Respir Cell Mol Biol 2020; 61:312-321. [PMID: 30896965 DOI: 10.1165/rcmb.2017-0387oc] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Primary ciliary dyskinesia (PCD) is a genetically and phenotypically heterogeneous disease caused by mutations in over 40 different genes. Individuals with PCD caused by mutations in RSPH1 (radial spoke head 1 homolog) have been reported to have a milder phenotype than other individuals with PCD, as evidenced by a lower incidence of neonatal respiratory distress, higher nasal nitric oxide concentrations, and better lung function. To better understand genotype-phenotype relationships in PCD, we have characterized a mutant mouse model with a deletion of Rsph1. Approximately 50% of cilia from Rsph1-/- cells appeared normal by transmission EM, whereas the remaining cilia revealed a range of defects, primarily transpositions or a missing central pair. Ciliary beat frequency in Rsph1-/- cells was significantly lower than in control cells (20.2 ± 0.8 vs. 25.0 ± 0.9 Hz), and the cilia exhibited an aberrant rotational waveform. Young Rsph1-/- animals demonstrated a low rate of mucociliary clearance in the nasopharynx that was reduced to zero by about 1 month of age. Rsph1-/- animals accumulated mucus in the nasal cavity but had a lower bacterial burden than animals with a deletion of dynein axonemal intermediate chain 1 (Dnaic1-/-). Thus, Rsph1-/- mice display a PCD phenotype similar to but less severe than that observed in Dnaic1-/- mice, similar to what has been observed in humans. The results suggest that some individuals with PCD may not have a complete loss of mucociliary clearance and further suggest that early diagnosis and intervention may be important to maintain this low amount of clearance.
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Affiliation(s)
- Weining Yin
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Alessandra Livraghi-Butrico
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Patrick R Sears
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Troy D Rogers
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Kimberlie A Burns
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Barbara R Grubb
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Lawrence E Ostrowski
- Marsico Lung Institute/Cystic Fibrosis Center, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
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10
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Chivukula RR, Montoro DT, Leung HM, Yang J, Shamseldin HE, Taylor MS, Dougherty GW, Zariwala MA, Carson J, Daniels MLA, Sears PR, Black KE, Hariri LP, Almogarri I, Frenkel EM, Vinarsky V, Omran H, Knowles MR, Tearney GJ, Alkuraya FS, Sabatini DM. Author Correction: A human ciliopathy reveals essential functions for NEK10 in airway mucociliary clearance. Nat Med 2020; 26:300. [PMID: 31996837 DOI: 10.1038/s41591-020-0773-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An amendment to this paper has been published and can be accessed via a link at the top of the paper.
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Affiliation(s)
- Raghu R Chivukula
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA. .,Whitehead Institute for Biomedical Research, Cambridge, MA, USA. .,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA. .,Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA. .,Koch Institute for Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Daniel T Montoro
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Hui Min Leung
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Jason Yang
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA.,Koch Institute for Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Martin S Taylor
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA.,Koch Institute for Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | - Gerard W Dougherty
- Department of General Pediatrics, University Children's Hospital Muenster, Münster, Germany
| | - Maimoona A Zariwala
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Johnny Carson
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - M Leigh Anne Daniels
- Division of Pulmonary Diseases and Critical Care Medicine, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Patrick R Sears
- Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Katharine E Black
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Lida P Hariri
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | - Ibrahim Almogarri
- Department of Pediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Evgeni M Frenkel
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA.,Koch Institute for Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Vladimir Vinarsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Heymut Omran
- Department of General Pediatrics, University Children's Hospital Muenster, Münster, Germany
| | - Michael R Knowles
- Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Guillermo J Tearney
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Department of Pathology, Massachusetts General Hospital, Boston, MA, USA.,Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA.,Koch Institute for Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
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11
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Chivukula RR, Montoro DT, Leung HM, Yang J, Shamseldin HE, Taylor MS, Dougherty GW, Zariwala MA, Carson J, Daniels MLA, Sears PR, Black KE, Hariri LP, Almogarri I, Frenkel EM, Vinarsky V, Omran H, Knowles MR, Tearney GJ, Alkuraya FS, Sabatini DM. A human ciliopathy reveals essential functions for NEK10 in airway mucociliary clearance. Nat Med 2020; 26:244-251. [PMID: 31959991 PMCID: PMC7018620 DOI: 10.1038/s41591-019-0730-x] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 12/06/2019] [Indexed: 12/16/2022]
Affiliation(s)
- Raghu R Chivukula
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA. .,Whitehead Institute for Biomedical Research, Cambridge, MA, USA. .,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA. .,Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA. .,Koch Institute for Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.
| | - Daniel T Montoro
- Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA
| | - Hui Min Leung
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA
| | - Jason Yang
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA.,Koch Institute for Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Hanan E Shamseldin
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Martin S Taylor
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA.,Koch Institute for Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | - Gerard W Dougherty
- Department of General Pediatrics, University Children's Hospital Muenster, Münster, Germany
| | - Maimoona A Zariwala
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Johnny Carson
- Department of Pediatrics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - M Leigh Anne Daniels
- Division of Pulmonary Diseases and Critical Care Medicine, Department of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Patrick R Sears
- Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Katharine E Black
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Lida P Hariri
- Department of Pathology, Massachusetts General Hospital, Boston, MA, USA
| | - Ibrahim Almogarri
- Department of Pediatrics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - Evgeni M Frenkel
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA.,Koch Institute for Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Vladimir Vinarsky
- Division of Pulmonary and Critical Care Medicine, Department of Medicine, Massachusetts General Hospital, Boston, MA, USA
| | - Heymut Omran
- Department of General Pediatrics, University Children's Hospital Muenster, Münster, Germany
| | - Michael R Knowles
- Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.,Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Guillermo J Tearney
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA.,Harvard Medical School, Boston, MA, USA.,Department of Pathology, Massachusetts General Hospital, Boston, MA, USA.,Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
| | - Fowzan S Alkuraya
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia.
| | - David M Sabatini
- Whitehead Institute for Biomedical Research, Cambridge, MA, USA.,Howard Hughes Medical Institute, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA.,Broad Institute of Massachusetts Institute of Technology and Harvard, Cambridge, MA, USA.,Koch Institute for Integrative Cancer Research, Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
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12
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Bustamante-Marin XM, Shapiro A, Sears PR, Charng WL, Conrad DF, Leigh MW, Knowles MR, Ostrowski LE, Zariwala MA. Identification of genetic variants in CFAP221 as a cause of primary ciliary dyskinesia. J Hum Genet 2019; 65:175-180. [PMID: 31636325 PMCID: PMC6920546 DOI: 10.1038/s10038-019-0686-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 10/02/2019] [Accepted: 10/03/2019] [Indexed: 12/15/2022]
Abstract
Primary ciliary dyskinesia (PCD) is a rare disorder that affects the biogenesis or function of motile cilia resulting in chronic airway disease. PCD is genetically and phenotypically heterogeneous, with causative mutations identified in over 40 genes; however, the genetic basis of many cases is unknown. Using whole exome sequencing, we identified three affected siblings with clinical symptoms of PCD but normal ciliary structure, carrying compound heterozygous loss-of-function variants in CFAP221. Computational analysis suggests that these variants are the most damaging alleles shared by all three siblings. Nasal epithelial cells from one of the subjects demonstrated slightly reduced beat frequency (16.5 Hz vs 17.7 Hz, p=0.16); however, waveform analysis revealed that the CFAP221 defective cilia beat in an aberrant circular pattern. These results show that genetic variants in CFAP221 cause PCD and that CFAP221 should be considered a candidate gene in cases where PCD is suspected but cilia structure and beat frequency appear normal.
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Affiliation(s)
- Ximena M Bustamante-Marin
- Department of Medicine, Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Adam Shapiro
- Department of Pediatrics, Division of Pediatric Respiratory Medicine, McGill University Health Centre Research Institute, Montreal, QC, Canada
| | - Patrick R Sears
- Department of Medicine, Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Wu-Lin Charng
- Department of Genetics and Psychiatry, Washington University School of Medicine, St. Louis, MO, 63110, USA
| | - Donald F Conrad
- Department of Genetics and Psychiatry, Washington University School of Medicine, St. Louis, MO, 63110, USA.,Division of Genetics, Oregon National Primate Research Center, Beaverton, OR, 97006, USA
| | - Margaret W Leigh
- Department of Pediatrics, Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Michael R Knowles
- Department of Medicine, Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, 27599, USA
| | - Lawrence E Ostrowski
- Department of Medicine, Marsico Lung Institute, University of North Carolina, Chapel Hill, NC, 27599, USA.
| | - Maimoona A Zariwala
- Department of Pathology and Laboratory Medicine, Marsico Lung Institute University of North Carolina, Chapel Hill, NC, 27599, USA.
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13
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Blackmon RL, Kreda SM, Sears PR, Chapman BS, Hill DB, Tracy JB, Ostrowski LE, Oldenburg AL. Direct monitoring of pulmonary disease treatment biomarkers using plasmonic gold nanorods with diffusion-sensitive OCT. Nanoscale 2017; 9:4907-4917. [PMID: 28358158 PMCID: PMC5473168 DOI: 10.1039/c7nr00376e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
The solid concentration of pulmonary mucus (wt%) is critical to respiratory health. In patients with respiratory disease, such as Cystic Fibrosis (CF) and Chronic Obstructive Pulmonary Disorder (COPD), mucus hydration is impaired, resulting in high wt%. Mucus with high wt% is a hallmark of pulmonary disease that leads to obstructed airways, inflammation, and infection. Methods to measure mucus hydration in situ and in real-time are needed for drug development and personalized therapy. We employed plasmonic gold nanorod (GNR) biosensors that intermittently collide with macromolecules comprising the mucus mesh as they self-diffuse, such that GNR translational diffusion (DT) is sensitive to wt%. GNRs are attractive candidates for bioprobes due to their anisotropic optical scattering that makes them easily distinguishable from native tissue using polarization-sensitive OCT. Using principles of heterodyne dynamic light scattering, we developed diffusion-sensitive optical coherence tomography (DS-OCT) to spatially-resolve changing DT in real-time. DS-OCT enables, for the first time, direct monitoring of changes in nanoparticle diffusion rates that are sensitive to nanoporosity with spatial and temporal resolutions of 4.7 μm and 0.2 s. DS-OCT therefore enables us to measure spatially-resolved changes in mucus wt% over time. In this study, we demonstrate the applicability of DS-OCT on well-differentiated primary human bronchial epithelial cells during a clinical mucus-hydrating therapy, hypertonic saline treatment (HST), to reveal, for the first time, mucus mixing, cellular secretions, and mucus hydration on the micrometer scale that translate to long-term therapeutic effects.
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Affiliation(s)
- R L Blackmon
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, NC 27599-3255, USA.
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14
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Barrick J, Doblas A, Gardner MR, Sears PR, Ostrowski LE, Oldenburg AL. High-speed and high-sensitivity parallel spectral-domain optical coherence tomography using a supercontinuum light source. Opt Lett 2016; 41:5620-5623. [PMID: 27973473 PMCID: PMC5235345 DOI: 10.1364/ol.41.005620] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The three most important metrics in optical coherence tomography (OCT) are resolution, speed, and sensitivity. Because there is a complex interplay between these metrics, no previous work has obtained the best performance in all three metrics simultaneously. We demonstrate that a high-power supercontinuum source, in combination with parallel spectral-domain OCT, achieves an unparalleled combination of resolution, speed, and sensitivity. This system captures cross-sectional images spanning 4 mm×0.5 mm at 1,024,000 lines/s with 2×14 μm resolution (axial×transverse) at a sensitivity of 113 dB. Imaging using the proposed system is demonstrated on highly differentiated human bronchial epithelial cells to capture and spatially localize ciliary dynamics.
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15
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Blackmon RL, Kreda SM, Sears PR, Ostrowski LE, Hill DB, Chapman BS, Tracy JB, Oldenburg AL. Diffusion-sensitive optical coherence tomography for real-time monitoring of mucus thinning treatments. Proc SPIE Int Soc Opt Eng 2016; 9697:969724. [PMID: 27746581 PMCID: PMC5061133 DOI: 10.1117/12.2208805] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Mucus hydration (wt%) has become an increasingly useful metric in real-time assessment of respiratory health in diseases like cystic fibrosis and COPD, with higher wt% indicative of diseased states. However, available in vivo rheological techniques are lacking. Gold nanorods (GNRs) are attractive biological probes whose diffusion through tissue is sensitive to the correlation length of comprising biopolymers. Through employment of dynamic light scattering theory on OCT signals from GNRs, we find that weakly-constrained GNR diffusion predictably decreases with increasing wt% (more disease-like) mucus. Previously, we determined this method is robust against mucus transport on human bronchial epithelial (hBE) air-liquid interface cultures (R2=0.976). Here we introduce diffusion-sensitive OCT (DS-OCT), where we collect M-mode image ensembles, from which we derive depth- and temporally-resolved GNR diffusion rates. DS-OCT allows for real-time monitoring of changing GNR diffusion as a result of topically applied mucus-thinning agents, enabling monitoring of the dynamics of mucus hydration never before seen. Cultured human airway epithelial cells (Calu-3) with a layer of endogenous mucus were doped with topically deposited GNRs (80×22nm), and subsequently treated with hypertonic saline (HS) or isotonic saline (IS). DS-OCT provided imaging of the mucus thinning response up to a depth of 600μm with 4.65μm resolution, over a total of 8 minutes in increments of ≥3 seconds. For both IS and HS conditions, DS-OCT captured changes in the pattern of mucus hydration over time. DS-OCT opens a new window into understanding mechanisms of mucus thinning during treatment, enabling real-time efficacy feedback needed to optimize and tailor treatments for individual patients.
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Affiliation(s)
- Richard L Blackmon
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, NC 27599
| | - Silvia M Kreda
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, NC 27599
| | - Patrick R Sears
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, NC 27599
| | - Lawrence E Ostrowski
- Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, NC 27599
| | - David B Hill
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, NC 27599; Marsico Lung Institute/Cystic Fibrosis Research and Treatment Center, University of North Carolina at Chapel Hill, NC 27599
| | - Brian S Chapman
- Department of Material Science & Engineering, North Carolina State University, Raleigh, NC 27695
| | - Joseph B Tracy
- Department of Material Science & Engineering, North Carolina State University, Raleigh, NC 27695
| | - Amy L Oldenburg
- Department of Physics and Astronomy, University of North Carolina at Chapel Hill, NC 27599
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16
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Sears PR, Yin WN, Ostrowski LE. Continuous mucociliary transport by primary human airway epithelial cells in vitro. Am J Physiol Lung Cell Mol Physiol 2015; 309:L99-108. [PMID: 25979076 DOI: 10.1152/ajplung.00024.2015] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 05/11/2015] [Indexed: 11/22/2022] Open
Abstract
Mucociliary clearance (MCC) is an important innate defense mechanism that continuously removes inhaled pathogens and particulates from the airways. Normal MCC is essential for maintaining a healthy respiratory system, and impaired MCC is a feature of many airway diseases, including both genetic (cystic fibrosis, primary ciliary dyskinesia) and acquired (chronic obstructive pulmonary disease, bronchiectasis) disorders. Research into the fundamental processes controlling MCC, therefore, has direct clinical application, but has been limited in part due to the difficulty of studying this complex multicomponent system in vitro. In this study, we have characterized a novel method that allows human airway epithelial cells to differentiate into a mucociliary epithelium that transports mucus in a continuous circular track. The mucociliary transport device allows the measurement and manipulation of all features of mucociliary transport in a controlled in vitro system. In this initial study, the effect of ciliary beat frequency and mucus concentration on the speed of mucociliary transport was investigated.
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Affiliation(s)
- Patrick R Sears
- Cystic Fibrosis/Pulmonary Research and Treatment Center, Marsico Lung Institute, Department of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Wei-Ning Yin
- Cystic Fibrosis/Pulmonary Research and Treatment Center, Marsico Lung Institute, Department of Medicine, University of North Carolina, Chapel Hill, North Carolina
| | - Lawrence E Ostrowski
- Cystic Fibrosis/Pulmonary Research and Treatment Center, Marsico Lung Institute, Department of Medicine, University of North Carolina, Chapel Hill, North Carolina
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Teves ME, Sears PR, Li W, Zhang Z, Tang W, van Reesema L, Costanzo RM, Davis CW, Knowles MR, Strauss JF, Zhang Z. Sperm-associated antigen 6 (SPAG6) deficiency and defects in ciliogenesis and cilia function: polarity, density, and beat. PLoS One 2014; 9:e107271. [PMID: 25333478 PMCID: PMC4204823 DOI: 10.1371/journal.pone.0107271] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Accepted: 08/14/2014] [Indexed: 12/28/2022] Open
Abstract
SPAG6, an axoneme central apparatus protein, is essential for function of ependymal cell cilia and sperm flagella. A significant number of Spag6-deficient mice die with hydrocephalus, and surviving males are sterile because of sperm motility defects. In further exploring the ciliary dysfunction in Spag6-null mice, we discovered that cilia beat frequency was significantly reduced in tracheal epithelial cells, and that the beat was not synchronized. There was also a significant reduction in cilia density in both brain ependymal and trachea epithelial cells, and cilia arrays were disorganized. The orientation of basal feet, which determines the direction of axoneme orientation, was apparently random in Spag6-deficient mice, and there were reduced numbers of basal feet, consistent with reduced cilia density. The polarized epithelial cell morphology and distribution of intracellular mucin, α-tubulin, and the planar cell polarity protein, Vangl2, were lost in Spag6-deficient tracheal epithelial cells. Polarized epithelial cell morphology and polarized distribution of α-tubulin in tracheal epithelial cells was observed in one-week old wild-type mice, but not in the Spag6-deficient mice of the same age. Thus, the cilia and polarity defects appear prior to 7 days post-partum. These findings suggest that SPAG6 not only regulates cilia/flagellar motility, but that in its absence, ciliogenesis, axoneme orientation, and tracheal epithelial cell polarity are altered.
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Affiliation(s)
- Maria E. Teves
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Patrick R. Sears
- Cystic Fibrosis Center, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Wei Li
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Zhengang Zhang
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Infectious Diseases, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Waixing Tang
- Department of Otorhinolaryngology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Lauren van Reesema
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Richard M. Costanzo
- Department of Physiology and Biophysics, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - C. William Davis
- Department of Cell & Molecular Physiology of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Michael R. Knowles
- Department of Cell & Molecular Physiology of Medicine, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Jerome F. Strauss
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, United States of America
| | - Zhibing Zhang
- Department of Obstetrics and Gynecology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University, Richmond, Virginia, United States of America
- * E-mail:
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Knowles MR, Ostrowski LE, Leigh MW, Sears PR, Davis SD, Wolf WE, Hazucha MJ, Carson JL, Olivier KN, Sagel SD, Rosenfeld M, Ferkol TW, Dell SD, Milla CE, Randell SH, Yin W, Sannuti A, Metjian HM, Noone PG, Noone PJ, Olson CA, Patrone MV, Dang H, Lee HS, Hurd TW, Gee HY, Otto EA, Halbritter J, Kohl S, Kircher M, Krischer J, Bamshad MJ, Nickerson DA, Hildebrandt F, Shendure J, Zariwala MA. Mutations in RSPH1 cause primary ciliary dyskinesia with a unique clinical and ciliary phenotype. Am J Respir Crit Care Med 2014; 189:707-17. [PMID: 24568568 DOI: 10.1164/rccm.201311-2047oc] [Citation(s) in RCA: 167] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
RATIONALE Primary ciliary dyskinesia (PCD) is a genetically heterogeneous recessive disorder of motile cilia, but the genetic cause is not defined for all patients with PCD. OBJECTIVES To identify disease-causing mutations in novel genes, we performed exome sequencing, follow-up characterization, mutation scanning, and genotype-phenotype studies in patients with PCD. METHODS Whole-exome sequencing was performed using NimbleGen capture and Illumina HiSeq sequencing. Sanger-based sequencing was used for mutation scanning, validation, and segregation analysis. MEASUREMENTS AND MAIN RESULTS We performed exome sequencing on an affected sib-pair with normal ultrastructure in more than 85% of cilia. A homozygous splice-site mutation was detected in RSPH1 in both siblings; parents were carriers. Screening RSPH1 in 413 unrelated probands, including 325 with PCD and 88 with idiopathic bronchiectasis, revealed biallelic loss-of-function mutations in nine additional probands. Five affected siblings of probands in RSPH1 families harbored the familial mutations. The 16 individuals with RSPH1 mutations had some features of PCD; however, nasal nitric oxide levels were higher than in patients with PCD with other gene mutations (98.3 vs. 20.7 nl/min; P < 0.0003). Additionally, individuals with RSPH1 mutations had a lower prevalence (8 of 16) of neonatal respiratory distress, and later onset of daily wet cough than typical for PCD, and better lung function (FEV1), compared with 75 age- and sex-matched PCD cases (73.0 vs. 61.8, FEV1 % predicted; P = 0.043). Cilia from individuals with RSPH1 mutations had normal beat frequency (6.1 ± Hz at 25°C), but an abnormal, circular beat pattern. CONCLUSIONS The milder clinical disease and higher nasal nitric oxide in individuals with biallelic mutations in RSPH1 provides evidence of a unique genotype-phenotype relationship in PCD, and suggests that mutations in RSPH1 may be associated with residual ciliary function.
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Abstract
Airway cilia depend on precise changes in shape to transport the mucus gel overlying mucosal surfaces. The ciliary motion can be recorded in several planes using video microscopy. However, cilia are densely packed, and automated computerized systems are not available to convert these ciliary shape changes into forms that are useful for testing theoretical models of ciliary function. We developed a system for converting planar ciliary motions recorded by video microscopy into an empirical quantitative model, which is easy to use in validating mathematical models, or in examining ciliary function, e.g., in primary ciliary dyskinesia (PCD). The system we developed allows the manipulation of a model cilium superimposed over a video of beating cilia. Data were analyzed to determine shear angles and velocity vectors of points along the cilium. Extracted waveforms were used to construct a composite waveform, which could be used as a standard. Variability was measured as the mean difference in position of points on individual waveforms and the standard. The shapes analyzed were the end-recovery, end-effective, and fastest moving effective and recovery with mean (± SE) differences of 0.31(0.04), 0.25(0.06), 0.50(0.12), 0.50(0.10), μm, respectively. In contrast, the same measures for three different PCD waveforms had values far outside this range.
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Affiliation(s)
- Patrick R Sears
- Cystic Fibrosis Center, University of North Carolina, 6026 Thurston-Bowles Bldg., CB7248, Chapel Hill, NC 27599, USA.
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Sears PR, Davis CW, Chua M, Sheehan JK. Mucociliary interactions and mucus dynamics in ciliated human bronchial epithelial cell cultures. Am J Physiol Lung Cell Mol Physiol 2011; 301:L181-6. [PMID: 21531774 DOI: 10.1152/ajplung.00321.2010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The airway epithelial surface liquid is generally considered to be composed of two layers, a periciliary layer and a continuous thick mucus layer moving in bulk. This view may not be appropriate for all areas of the lung. Our hypothesis, that mucus may form a discontinuous layer with dynamic attachments to the surface, is investigated using a culture system. We used live-cell confocal microscopy to investigate thin mucus layers and fluorescent beads and exogenous MUC5B to visualize mucus dynamics on ciliated human bronchial cultures. A continuous mucus layer was not observed. In sparsely ciliated cultures, mucus attached to ciliated cells; however, in highly ciliated cultures, mucus formed strands several hundred micrometers long. As with increases in ciliation, increases in bead concentration caused the appearance of mucus strands. We confirmed the involvement of mucins in the binding of mucus to cilia by adding labeled purified MUC5B to the cultures. These data suggest that mucins may have an intrinsic ability to form attachments to cilia. The significance of these findings is that aberrant modulation of such an intrinsic property may explain the initiation of highly adherent mucus in cystic fibrosis lung disease.
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Affiliation(s)
- Patrick R Sears
- Cystic Fibrosis Center, University of North Carolina, Chapel Hill, NC 27599, USA.
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Abstract
SPOC1 airway goblet cells secrete mucin in response to P2Y2 receptor agonists and to secretagogues, phorbol 12-myristate 13-acetate (PMA) and ionomycin, which mobilize elements of the phospholipase C pathway, PKC and Ca2+, respectively. Previous studies demonstrated that mucin secretion from SLO-permeabilized, EGTA-buffered SPOC1 cells was stimulated by PMA at low Ca2+ levels (< 0.1 microm), consistent with the notion that regulated exocytosis may occur by Ca2+-independent pathways. We tested the alternative hypothesis that PMA-induced mucin secretion is, in fact, a Ca2+-dependent process under the conditions of low bulk Ca2+, one that is permitted in the typical SLO-permeabilized cell model by the slow binding kinetics of EGTA. Both IP3 and elevated bulk Ca2+ activated mucin secretion in SPOC1 cells buffered by EGTA, suggesting that IP3 generates a local Ca2+ gradient in the vicinity of the secretory granules to the degree necessary to trigger exocytosis. BAPTA, which binds Ca2+ approximately 100-fold faster than EGTA, diminished IP3-induced mucin release over a range of concentrations by > or = 69%, yet maintained an essentially normal mucin secretory response to elevated bulk Ca2+ in permeabilized SPOC1 cells. BAPTA also diminished the mucin secretory response of permeabilized cells to PMA, relative to the EGTA-buffered control: at PMA below 30 nm, BAPTA abolished the secretory response, and at higher concentrations it was reduced significantly relative to the EGTA-buffered controls. PMA-induced secretion in EGTA was insensitive to heparin. These results suggest that Ca2+ is released locally during PMA-induced exocytosis, by an IP3-independent mechanism.
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Affiliation(s)
- Andrea H Rossi
- 6009 Thurston-Bowles, University of North Carolina, Chapel Hill, NC 27599-7248, USA
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Abstract
The electric field produced by cell membranes, extending only a few nanometers, is 1000 times stronger than the electric fields required to produce dissociation of molecular complexes. Using the complex formed by norepinephrine (NE) and ascorbic acid (AA), we have demonstrated the quantitative binding of AA to NE, the use of capillary electrophoresis to measure quantitative binding of nonelectrolyte complexes, the determination of a dissociation constant (Kd) from electric field-dissociation constants (Ke), and a model for natural dissociation of the NE-AA complex due to the electric field generated by a cell membrane. NE-AA dissociation constants show little effect of NE concentration or pH changes. NE-related compounds also bind AA: epinephrine > norepinephrine > tyrosine > histamine > phenylalanine. Serotonin does not bind AA. Phosphorylated AA and glucose also bind NE at 0.05 and 0.08 of the AA binding, respectively. Natural electrophoresis of molecular complexes allows compounds to travel through the body in a protected state and still be available for physiological activity upon reaching a membrane.
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Affiliation(s)
- P F Dillon
- Department of Physiology, Michigan State University, East Lansing, Michigan 48823, USA.
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Abstract
The interaction of pyruvate kinase from skeletal (SKPK) and smooth (SMPK) muscle with MM-creatine kinase (MMCK) and BB-creatine kinase (BBCK) was assessed using temporal absorbance changes, variations in absorbance at different wavelengths, concentration dependence, association in an electric field, and PK kinetic activity. SKPK exhibits a time course of absorbance increase in the presence of MMCK with a time constant of 29.5 min. This increase occurs at all wavelength from 240 to 1000 nm. At 195 nm, the combination of SKPK and MMCK produces a decrease in absorption with electric fields of both 0 and 204 V/cm. The change in SKPK-MMCK is saturable. SKPK activity is significantly increased by the presence of MMCK in solutions of 0-32% ethanol. These results indicate specific SKPK-MMCK interaction. SMPK and BBCK did not exhibit similar coupling when the BBCK concentration dependence of absorbance or SMPK activity in solutions of 0-32% ethanol was determined. Both MMCK and BBCK increased SKPK activity; neither MMCK nor BBCK increased SMPK activity. The ability to form diazymatic complexes with creatine kinase appears to reside in SKPK. This coupling may account for the increased flux through PK without significant substrate changes seen during skeletal muscle activation. This coupling will not occur in smooth muscle.
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Affiliation(s)
- P R Sears
- Department of Physiology, 108 Giltner Hall, Michigan State University, East Lansing, Michigan 48824, USA
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Abstract
A method for the measurement of tissue metabolites from rabbit urinary bladder using capillary electrophoresis (CE) has been developed. The method generates a reproducible electropherogram containing > 20 peaks, including NAD, NADH, lactate, UDP-glucose, phosphocreatine, creatine, ATP, ADP, GTP, and UTP, from < 20 nl of extract solution generated from 1.1 nl (or approximately 1.2 micrograms) of tissue in < 40 min. Multiple samples from the same bladder produce SE comparable with enzymatic or nuclear magnetic resonance (NMR) measurements of metabolites: phosphorus-NMR measurement requires 10(6) more tissue than CE; individual enzymatic measurements using 100 microliters/sample require 2,000 microliters, a 10(5) greater volume than required by CE for the same number of metabolites. CE detects about three times more peaks than phosphorus-NMR on a similar time scale. Comparable measurements using enzymatic analysis would require approximately 10 times longer. The combination of minimal tissue volume requirements, rapid measurement, and reproducibility makes CE a valuable tool in the investigation of simultaneous changes in multiple metabolites from minute tissue samples.
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Affiliation(s)
- P F Dillon
- Department of Physiology, Michigan State University, East Lansing 48824, USA
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