1
|
Kudrna K, Staab EB, Eilers E, Thomes P, Maurya S, Brody SL, Wyatt TA, Bailey KL, Dickinson JD. mTOR signaling regulates aberrant epithelial cell proliferative and migratory behaviors characteristic of airway mucous metaplasia in asthma. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.12.579905. [PMID: 38405874 PMCID: PMC10888751 DOI: 10.1101/2024.02.12.579905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
In asthma, the airway epithelium is hyperplastic, hypertrophied, and lined with numerous large MUC5AC-containing goblet cells (GC). Furthermore, the normal epithelial architecture is disorganized with numerous, what we here describe as, ectopic goblet cells (eGC) deep within the thickened epithelial layer disconnected from the lumenal surface. mTOR is a highly conserved pathway that regulates cell size and proliferation. We hypothesized that the balance between mTOR and autophagy signaling regulates key features of the asthma epithelial layer. Airway histological sections from subjects with asthma had increased frequency of eGC and increased levels of mTOR phosphorylation target-Ribosomal S6. Using human airway epithelial cells (hAECs) with IL-13 stimulation and timed withdrawal to stimulate resolution, we found that multiple key downstream phosphorylation targets downstream from the mTOR complex were increased during early IL-13-mediated mucous metaplasia, and then significantly declined during resolution. The IL-13-mediated changes in mTOR signaling were paralleled by morphologic changes with airway epithelial hypertrophy, hyperplasia, and frequency of eGC. We then examined the relationship between mTOR and autophagy using mice deficient in autophagy protein Atg16L1. Despite having increased cytoplasmic mucins, mouse AECs from Atg16L1 deficient mice had no significant difference in mTOR downstream signaling. mTOR inhibition with rapamycin led to a loss of IL-13-mediated epithelial hypertrophy, hyperplasia, ectopic GC distribution, and reduction in cytoplasmic MUC5AC levels. mTOR inhibition was also associated with a reduction in aberrant IL-13-mediated hAEC proliferation and migration. Our findings demonstrate that mTOR signaling is associated with mucous metaplasia and is crucial to the disorganized airway epithelial structure and function characteristic of muco-obstructive airway diseases such as asthma. Graphical Abstract Key Concepts The airway epithelium in asthma is disorganized and characterized by cellular proliferation, aberrant migration, and goblet cell mucous metaplasia.mTOR signaling is a dynamic process during IL-13-mediated mucous metaplasia, increasing with IL-13 stimulation and declining during resolution.mTOR signaling is strongly increased in the asthmatic airway epithelium.mTOR signaling is associated with the development of key features of the metaplastic airway epithelium including cell proliferation and ectopic distribution of goblet cells and aberrant cellular migration.Inhibition of mTOR leads to decreased epithelial hypertrophy, reduced ectopic goblet cells, and cellular migration.
Collapse
|
2
|
Nouri HR, Schaunaman N, Kraft M, Li L, Numata M, Chu HW. Tollip deficiency exaggerates airway type 2 inflammation in mice exposed to allergen and influenza A virus: role of the ATP/IL-33 signaling axis. Front Immunol 2023; 14:1304758. [PMID: 38124753 PMCID: PMC10731025 DOI: 10.3389/fimmu.2023.1304758] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 11/17/2023] [Indexed: 12/23/2023] Open
Abstract
Toll-interacting protein (Tollip) is a negative regulator of the pro-inflammatory response to viruses, including influenza A virus (IAV). Genetic variation of Tollip has been associated with reduced airway epithelial Tollip expression and poor lung function in patients with asthma. Whether Tollip deficiency exaggerates type 2 inflammation (e.g., eosinophils) and viral infection in asthma remains unclear. We sought to address this critical, but unanswered question by using a Tollip deficient mouse asthma model with IAV infection. Further, we determined the underlying mechanisms by focusing on the role of the ATP/IL-33 signaling axis. Wild-type and Tollip KO mice were intranasally exposed to house dust mite (HDM) and IAV with or without inhibitors for IL-33 (i.e., soluble ST2, an IL-33 decoy receptor) and ATP signaling (i.e., an antagonist of the ATP receptor P2Y13). Tollip deficiency amplified airway type 2 inflammation (eosinophils, IL-5, IL-13 and mucins), and the release of ATP and IL-33. Blocking ATP receptor P2Y13 decreased IL-33 release during IAV infection in HDM-challenged Tollip KO mice. Furthermore, soluble ST2 attenuated airway eosinophilic inflammation in Tollip KO mice treated with HDM and IAV. HDM challenges decreased lung viral load in wild-type mice, but Tollip deficiency reduced the protective effects of HDM challenges on viral load. Our data suggests that during IAV infection, Tollip deficiency amplified type 2 inflammation and delayed viral clearance, in part by promoting ATP signaling and subsequent IL-33 release. Our findings may provide several therapeutic targets, including ATP and IL-33 signaling inhibition for attenuating excessive airway type 2 inflammation in human subjects with Tollip deficiency and IAV infection.
Collapse
Affiliation(s)
- Hamid Reza Nouri
- Department of Medicine, National Jewish Health, Denver, CO, United States
| | | | - Monica Kraft
- Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Liwu Li
- Department of Biological Sciences, College of Science, Virginia Tech, Blacksburg, VA, United States
| | - Mari Numata
- Department of Medicine, National Jewish Health, Denver, CO, United States
| | - Hong Wei Chu
- Department of Medicine, National Jewish Health, Denver, CO, United States
| |
Collapse
|
3
|
Gustafsson JK, Johansson MEV. The role of goblet cells and mucus in intestinal homeostasis. Nat Rev Gastroenterol Hepatol 2022; 19:785-803. [PMID: 36097076 DOI: 10.1038/s41575-022-00675-x] [Citation(s) in RCA: 128] [Impact Index Per Article: 64.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 08/04/2022] [Indexed: 12/08/2022]
Abstract
The intestinal tract faces numerous challenges that require several layers of defence. The tight epithelium forms a physical barrier that is further protected by a mucus layer, which provides various site-specific protective functions. Mucus is produced by goblet cells, and as a result of single-cell RNA sequencing identifying novel goblet cell subpopulations, our understanding of their various contributions to intestinal homeostasis has improved. Goblet cells not only produce mucus but also are intimately linked to the immune system. Mucus and goblet cell development is tightly regulated during early life and synchronized with microbial colonization. Dysregulation of the developing mucus systems and goblet cells has been associated with infectious and inflammatory conditions and predisposition to chronic disease later in life. Dysfunctional mucus and altered goblet cell profiles are associated with inflammatory conditions in which some mucus system impairments precede inflammation, indicating a role in pathogenesis. In this Review, we present an overview of the current understanding of the role of goblet cells and the mucus layer in maintaining intestinal health during steady-state and how alterations to these systems contribute to inflammatory and infectious disease.
Collapse
Affiliation(s)
- Jenny K Gustafsson
- Department of Physiology, Institute of Neuroscience and Physiology, University of Gothenburg, Gothenburg, Sweden
| | - Malin E V Johansson
- Department of Medical Biochemisty and Cell biology, Institute of Biomedicine, University of Gothenburg, Gothenburg, Sweden.
| |
Collapse
|
4
|
Hoang ON, Ermund A, Jaramillo AM, Fakih D, French CB, Flores JR, Karmouty-Quintana H, Magnusson JM, Fois G, Fauler M, Frick M, Braubach P, Hales JB, Kurten RC, Panettieri R, Vergara L, Ehre C, Adachi R, Tuvim MJ, Hansson GC, Dickey BF. Mucins MUC5AC and MUC5B Are Variably Packaged in the Same and in Separate Secretory Granules. Am J Respir Crit Care Med 2022; 206:1081-1095. [PMID: 35776514 PMCID: PMC9704839 DOI: 10.1164/rccm.202202-0309oc] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 07/01/2022] [Indexed: 01/27/2023] Open
Abstract
Rationale: MUC5AC (mucin 5AC, oligomeric gel-forming) and MUC5B (mucin 5B, oligomeric gel-forming) are the predominant secreted polymeric mucins in mammalian airways. They contribute differently to the pathogenesis of various muco-obstructive and interstitial lung diseases, and their genes are separately regulated, but whether they are packaged together or in separate secretory granules is not known. Objectives: To determine the packaging of MUC5AC and MUC5B within individual secretory granules in mouse and human airways under varying conditions of inflammation and along the proximal-distal axis. Methods: Lung tissue was obtained from mice stimulated to upregulate mucin production by the cytokines IL-1β and IL-13 or by porcine pancreatic elastase. Human lung tissue was obtained from donated normal lungs, biopsy samples of transplanted lungs, and explanted lungs from subjects with chronic obstructive pulmonary disease. MUC5AC and MUC5B were labeled with antibodies from different animal species or, in mice only, by transgenic chimeric mucin-fluorescent proteins and imaged using widefield deconvolution or Airyscan fluorescence microscopy. Measurements and Main Results: In both mouse and human airways, most secretory granules contained both mucins interdigitating within the granules. Smaller numbers of granules contained MUC5B alone, and even fewer contained MUC5AC alone. Conclusions: MUC5AC and MUC5B are variably stored both in the same and in separate secretory granules of both mice and humans. The high fraction of granules containing both mucins under a variety of conditions makes it unlikely that their secretion can be differentially controlled as a therapeutic strategy. This work also advances knowledge of the packaging of mucins within secretory granules to understand mechanisms of epithelial stress in the pathogenesis of chronic lung diseases.
Collapse
Affiliation(s)
- Oanh N. Hoang
- Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Anna Ermund
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Ana M. Jaramillo
- Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Dalia Fakih
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Cory B. French
- Washington University School of Medicine, St. Louis, Missouri
| | - Jose R. Flores
- Washington University School of Medicine, St. Louis, Missouri
| | - Harry Karmouty-Quintana
- Division of Critical Care, Pulmonary, and Sleep Medicine, Department of Biochemistry and Molecular Biology, University of Texas Health Science Center at Houston, Houston, Texas
| | - Jesper M. Magnusson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Giorgio Fois
- Institute of General Physiology, Ulm University, Ulm, Germany
| | - Michael Fauler
- Institute of General Physiology, Ulm University, Ulm, Germany
| | - Manfred Frick
- Institute of General Physiology, Ulm University, Ulm, Germany
| | | | - Joshua B. Hales
- Washington University School of Medicine, St. Louis, Missouri
| | | | | | - Leoncio Vergara
- Institute of Biosciences and Technology, Texas A&M School of Medicine, Houston, Texas; and
| | - Camille Ehre
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Roberto Adachi
- Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Michael J. Tuvim
- Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Gunnar C. Hansson
- Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Gothenburg, Sweden
| | - Burton F. Dickey
- Department of Pulmonary Medicine, The University of Texas MD Anderson Cancer Center, Houston, Texas
| |
Collapse
|
5
|
Hill DB, Button B, Rubinstein M, Boucher RC. Physiology and pathophysiology of human airway mucus. Physiol Rev 2022; 102:1757-1836. [PMID: 35001665 PMCID: PMC9665957 DOI: 10.1152/physrev.00004.2021] [Citation(s) in RCA: 78] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 12/13/2021] [Accepted: 12/19/2021] [Indexed: 01/27/2023] Open
Abstract
The mucus clearance system is the dominant mechanical host defense system of the human lung. Mucus is cleared from the lung by cilia and airflow, including both two-phase gas-liquid pumping and cough-dependent mechanisms, and mucus transport rates are heavily dependent on mucus concentration. Importantly, mucus transport rates are accurately predicted by the gel-on-brush model of the mucociliary apparatus from the relative osmotic moduli of the mucus and periciliary-glycocalyceal (PCL-G) layers. The fluid available to hydrate mucus is generated by transepithelial fluid transport. Feedback interactions between mucus concentrations and cilia beating, via purinergic signaling, coordinate Na+ absorptive vs Cl- secretory rates to maintain mucus hydration in health. In disease, mucus becomes hyperconcentrated (dehydrated). Multiple mechanisms derange the ion transport pathways that normally hydrate mucus in muco-obstructive lung diseases, e.g., cystic fibrosis (CF), chronic obstructive pulmonary disease (COPD), non-CF bronchiectasis (NCFB), and primary ciliary dyskinesia (PCD). A key step in muco-obstructive disease pathogenesis is the osmotic compression of the mucus layer onto the airway surface with the formation of adherent mucus plaques and plugs, particularly in distal airways. Mucus plaques create locally hypoxic conditions and produce airflow obstruction, inflammation, infection, and, ultimately, airway wall damage. Therapies to clear adherent mucus with hydrating and mucolytic agents are rational, and strategies to develop these agents are reviewed.
Collapse
Affiliation(s)
- David B Hill
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Joint Department of Biomedical Engineering, The University of North Carolina and North Carolina State University, Chapel Hill, North Carolina
| | - Brian Button
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Michael Rubinstein
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
- Department of Mechanical Engineering and Materials Science, Biomedical Engineering, Physics, and Chemistry, Duke University, Durham, North Carolina
| | - Richard C Boucher
- Marsico Lung Institute, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| |
Collapse
|
6
|
Lai Y, Tuvim MJ, Leitz J, Peters J, Pfuetzner RA, Esquivies L, Zhou Q, Czako B, Cross JB, Jones P, Dickey BF, Brunger AT. Screening of Hydrocarbon-Stapled Peptides for Inhibition of Calcium-Triggered Exocytosis. Front Pharmacol 2022; 13:891041. [PMID: 35814209 PMCID: PMC9258623 DOI: 10.3389/fphar.2022.891041] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Accepted: 04/14/2022] [Indexed: 11/13/2022] Open
Abstract
The so-called primary interface between the SNARE complex and synaptotagmin-1 (Syt1) is essential for Ca2+-triggered neurotransmitter release in neuronal synapses. The interacting residues of the primary interface are conserved across different species for synaptotagmins (Syt1, Syt2, Syt9), SNAP-25, and syntaxin-1A homologs involved in fast synchronous release. This Ca2+-independent interface forms prior to Ca2+-triggering and plays a role in synaptic vesicle priming. This primary interface is also conserved in the fusion machinery that is responsible for mucin granule membrane fusion. Ca2+-stimulated mucin secretion is mediated by the SNAREs syntaxin-3, SNAP-23, VAMP8, Syt2, and other proteins. Here, we designed and screened a series of hydrocarbon-stapled peptides consisting of SNAP-25 fragments that included some of the key residues involved in the primary interface as observed in high-resolution crystal structures. We selected a subset of four stapled peptides that were highly α-helical as assessed by circular dichroism and that inhibited both Ca2+-independent and Ca2+-triggered ensemble lipid-mixing with neuronal SNAREs and Syt1. In a single-vesicle content-mixing assay with reconstituted neuronal SNAREs and Syt1 or with reconstituted airway SNAREs and Syt2, the selected peptides also suppressed Ca2+-triggered fusion. Taken together, hydrocarbon-stapled peptides that interfere with the primary interface consequently inhibit Ca2+-triggered exocytosis. Our inhibitor screen suggests that these compounds may be useful to combat mucus hypersecretion, which is a major cause of airway obstruction in the pathophysiology of COPD, asthma, and cystic fibrosis.
Collapse
Affiliation(s)
- Ying Lai
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, United States,*Correspondence: Axel T. Brunger, ; Ying Lai, ; Burton F. Dickey,
| | - Michael J. Tuvim
- Department of Pulmonary Medicine, MD Anderson Cancer Center, University of Texas, Houston, TX, United States
| | - Jeremy Leitz
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, United States
| | - John Peters
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, United States
| | - Richard A. Pfuetzner
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, United States,Howard Hughes Medical Institute, Stanford University, Stanford, CA, United States
| | - Luis Esquivies
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, United States,Howard Hughes Medical Institute, Stanford University, Stanford, CA, United States
| | - Qiangjun Zhou
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, United States
| | - Barbara Czako
- Institute for Applied Cancer Science, MD Anderson Cancer Center, University of Texas, Houston, TX, United States
| | - Jason B. Cross
- Institute for Applied Cancer Science, MD Anderson Cancer Center, University of Texas, Houston, TX, United States
| | - Philip Jones
- Institute for Applied Cancer Science, MD Anderson Cancer Center, University of Texas, Houston, TX, United States
| | - Burton F. Dickey
- Department of Pulmonary Medicine, MD Anderson Cancer Center, University of Texas, Houston, TX, United States,*Correspondence: Axel T. Brunger, ; Ying Lai, ; Burton F. Dickey,
| | - Axel T. Brunger
- Department of Molecular and Cellular Physiology, Stanford University, Stanford, CA, United States,Howard Hughes Medical Institute, Stanford University, Stanford, CA, United States,*Correspondence: Axel T. Brunger, ; Ying Lai, ; Burton F. Dickey,
| |
Collapse
|
7
|
Puntman DC, Arora S, Farina M, Toonen RF, Verhage M. Munc18-1 Is Essential for Neuropeptide Secretion in Neurons. J Neurosci 2021; 41:5980-5993. [PMID: 34103363 PMCID: PMC8276746 DOI: 10.1523/jneurosci.3150-20.2021] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 04/29/2021] [Accepted: 05/03/2021] [Indexed: 11/21/2022] Open
Abstract
Neuropeptide secretion from dense-core vesicles (DCVs) controls many brain functions. Several components of the DCV exocytosis machinery have recently been identified, but the participation of a SEC1/MUNC18 (SM) protein has remained elusive. Here, we tested the ability of the three exocytic SM proteins expressed in the mammalian brain, MUNC18-1/2/3, to support neuropeptide secretion. We quantified DCV exocytosis at a single vesicle resolution on action potential (AP) train-stimulation in mouse CNS neurons (of unknown sex) using pHluorin-tagged and/or mCherry-tagged neuropeptide Y (NPY) or brain-derived neurotrophic factor (BDNF). Conditional inactivation of Munc18-1 abolished all DCV exocytosis. Expression of MUNC18-1, but not MUNC18-2 or MUNC18-3, supported DCV exocytosis in Munc18-1 null neurons. Heterozygous (HZ) inactivation of Munc18-1, as a model for reduced MUNC18-1 expression, impaired DCV exocytosis, especially during the initial phase of train-stimulation, when the release was maximal. These data show that neurons critically and selectively depend on MUNC18-1 for neuropeptide secretion. Impaired neuropeptide secretion may explain aspects of the behavioral and neurodevelopmental phenotypes that were observed in Munc18-1 HZ mice.SIGNIFICANCE STATEMENT Neuropeptide secretion from dense-core vesicles (DCVs) modulates synaptic transmission, sleep, appetite, cognition and mood. However, the mechanisms of DCV exocytosis are poorly characterized. Here, we identify MUNC18-1 as an essential component for neuropeptide secretion from DCVs. Paralogs MUNC18-2 or MUNC18-3 cannot compensate for MUNC18-1. MUNC18-1 is the first protein identified to be essential for both neuropeptide secretion and synaptic transmission. In heterozygous (HZ) Munc18-1 neurons, that have a 50% reduced MUNC18-1expression and model the human STXBP1 syndrome, DCV exocytosis is impaired, especially during the initial phase of train-stimulation, when the release is maximal. These data show that MUNC18-1 is essential for neuropeptide secretion and that impaired neuropeptide secretion on reduced MUNC18-1expression may contribute to the symptoms of STXBP1 syndrome.
Collapse
Affiliation(s)
- Daniël C Puntman
- Section Functional genomics, Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research, Universitair Medisch Centrum, Amsterdam1081 HV, The Netherlands
| | - Swati Arora
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam1081 HV, The Netherlands
| | - Margherita Farina
- Section Functional genomics, Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research, Universitair Medisch Centrum, Amsterdam1081 HV, The Netherlands
| | - Ruud F Toonen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam1081 HV, The Netherlands
| | - Matthijs Verhage
- Section Functional genomics, Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research, Universitair Medisch Centrum, Amsterdam1081 HV, The Netherlands
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, Vrije Universiteit Amsterdam, Amsterdam1081 HV, The Netherlands
| |
Collapse
|
8
|
Sweeter JM, Kudrna K, Hunt K, Thomes P, Dickey BF, Brody SL, Dickinson JD. Autophagy of mucin granules contributes to resolution of airway mucous metaplasia. Sci Rep 2021; 11:13037. [PMID: 34158522 PMCID: PMC8219712 DOI: 10.1038/s41598-021-91932-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 06/01/2021] [Indexed: 12/21/2022] Open
Abstract
Exacerbations of muco-obstructive airway diseases such as COPD and asthma are associated with epithelial changes termed mucous metaplasia (MM). Many molecular pathways triggering MM have been identified; however, the factors that regulate resolution are less well understood. We hypothesized that the autophagy pathway is required for resolution of MM by eliminating excess non-secreted intracellular mucin granules. We found increased intracellular levels of mucins Muc5ac and Muc5b in mice deficient in autophagy regulatory protein, Atg16L1, and that this difference was not due to defects in the known baseline or stimulated mucin secretion pathways. Instead, we found that, in mucous secretory cells, Lc3/Lamp1 vesicles colocalized with mucin granules particularly adjacent to the nucleus, suggesting that some granules were being eliminated in the autophagy pathway rather than secreted. Using a mouse model of MM resolution, we found increased lysosomal proteolytic activity that peaked in the days after mucin production began to decline. In purified lysosomal fractions, Atg16L1-deficient mice had reduced proteolytic degradation of Lc3 and Sqstm1 and persistent accumulation of mucin granules associated with impaired resolution of mucous metaplasia. In normal and COPD derived human airway epithelial cells (AECs), activation of autophagy by mTOR inhibition led to a reduction of intracellular mucin granules in AECs. Our findings indicate that during peak and resolution phases of MM, autophagy activity rather than secretion is required for elimination of some remaining mucin granules. Manipulation of autophagy activation offers a therapeutic target to speed resolution of MM in airway disease exacerbations.
Collapse
Affiliation(s)
- J M Sweeter
- Pulmonary, Critical Care and Sleep Medicine Division, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - K Kudrna
- Pulmonary, Critical Care and Sleep Medicine Division, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - K Hunt
- Pulmonary, Critical Care and Sleep Medicine Division, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - P Thomes
- Pulmonary, Critical Care and Sleep Medicine Division, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA
| | - B F Dickey
- Department of Pulmonary Medicine, MD Anderson Cancer Center, Houston, TX, USA
| | - S L Brody
- Department of Medicine, Washington University School of Medicine, Saint Louis, MO, USA
| | - J D Dickinson
- Pulmonary, Critical Care and Sleep Medicine Division, Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA.
| |
Collapse
|
9
|
Nyström EEL, Martinez-Abad B, Arike L, Birchenough GMH, Nonnecke EB, Castillo PA, Svensson F, Bevins CL, Hansson GC, Johansson MEV. An intercrypt subpopulation of goblet cells is essential for colonic mucus barrier function. Science 2021; 372:372/6539/eabb1590. [PMID: 33859001 DOI: 10.1126/science.abb1590] [Citation(s) in RCA: 126] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2020] [Accepted: 03/05/2021] [Indexed: 12/11/2022]
Abstract
The intestinal mucus layer, an important element of epithelial protection, is produced by goblet cells. Intestinal goblet cells are assumed to be a homogeneous cell type. In this study, however, we delineated their specific gene and protein expression profiles and identified several distinct goblet cell populations that form two differentiation trajectories. One distinct subtype, the intercrypt goblet cells (icGCs), located at the colonic luminal surface, produced mucus with properties that differed from the mucus secreted by crypt-residing goblet cells. Mice with defective icGCs had increased sensitivity to chemically induced colitis and manifested spontaneous colitis with age. Furthermore, alterations in mucus and reduced numbers of icGCs were observed in patients with both active and remissive ulcerative colitis, which highlights the importance of icGCs in maintaining functional protection of the epithelium.
Collapse
Affiliation(s)
- Elisabeth E L Nyström
- Department of Medical Biochemistry, Institute of Biomedicine, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Beatriz Martinez-Abad
- Department of Medical Biochemistry, Institute of Biomedicine, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Liisa Arike
- Department of Medical Biochemistry, Institute of Biomedicine, University of Gothenburg, 40530 Gothenburg, Sweden
| | - George M H Birchenough
- Department of Medical Biochemistry, Institute of Biomedicine, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Eric B Nonnecke
- Department of Microbiology and Immunology, School of Medicine, University of California, Davis, CA 95616, USA
| | - Patricia A Castillo
- Department of Microbiology and Immunology, School of Medicine, University of California, Davis, CA 95616, USA
| | - Frida Svensson
- Department of Medical Biochemistry, Institute of Biomedicine, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Charles L Bevins
- Department of Microbiology and Immunology, School of Medicine, University of California, Davis, CA 95616, USA
| | - Gunnar C Hansson
- Department of Medical Biochemistry, Institute of Biomedicine, University of Gothenburg, 40530 Gothenburg, Sweden
| | - Malin E V Johansson
- Department of Medical Biochemistry, Institute of Biomedicine, University of Gothenburg, 40530 Gothenburg, Sweden.
| |
Collapse
|
10
|
Danahay H, Fox R, Lilley S, Charlton H, Adley K, Christie L, Ansari E, Ehre C, Flen A, Tuvim MJ, Dickey BF, Williams C, Beaudoin S, Collingwood SP, Gosling M. Potentiating TMEM16A does not stimulate airway mucus secretion or bronchial and pulmonary arterial smooth muscle contraction. FASEB Bioadv 2020; 2:464-477. [PMID: 32821878 PMCID: PMC7429354 DOI: 10.1096/fba.2020-00035] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2020] [Revised: 05/11/2020] [Accepted: 06/10/2020] [Indexed: 12/11/2022] Open
Abstract
The calcium-activated chloride channel (CaCC) TMEM16A enables chloride secretion across several transporting epithelia, including in the airways. Additional roles for TMEM16A have been proposed, which include regulating mucus production and secretion and stimulating smooth muscle contraction. The aim of the present study was to test whether the pharmacological regulation of TMEM16A channel function, could affect any of these proposed biological roles in the airways. In vitro, neither a potent and selective TMEM16A potentiator (ETX001) nor the potent TMEM16A inhibitor (Ani9) influenced either baseline mucin release or goblet cell numbers in well-differentiated primary human bronchial epithelial (HBE) cells. In vivo, a TMEM16A potentiator was without effect on goblet cell emptying in an IL-13 stimulated goblet cell metaplasia model. Using freshly isolated human bronchi and pulmonary arteries, neither ETX001 or Ani9 had any effect on the contractile or relaxant responses of the tissues. In vivo, ETX001 also failed to influence either lung or cardiovascular function when delivered directly into the airways of telemetered rats. Together, these studies do not support a role for TMEM16A in the regulation of goblet cell numbers or baseline mucin release, or on the regulation of airway or pulmonary artery smooth muscle contraction.
Collapse
Affiliation(s)
- Henry Danahay
- Enterprise Therapeutics Ltd, Science Park SquareBrightonUK
| | - Roy Fox
- School of Life SciencesUniversity of SussexBrightonUK
| | - Sarah Lilley
- School of Life SciencesUniversity of SussexBrightonUK
| | | | - Kathryn Adley
- School of Life SciencesUniversity of SussexBrightonUK
| | - Lee Christie
- REPROCELL Europe Ltd, West of Scotland Science ParkGlasgowUK
| | - Ejaz Ansari
- REPROCELL Europe Ltd, West of Scotland Science ParkGlasgowUK
| | - Camille Ehre
- Marsico Lung InstituteUniversity of North CarolinaChapel HillNCUSA
| | - Alexis Flen
- Marsico Lung InstituteUniversity of North CarolinaChapel HillNCUSA
| | - Michael J. Tuvim
- Department of Pulmonary MedicineThe University of Texas MD Anderson Cancer CenterHoustonTXUSA
| | - Burton F. Dickey
- Department of Pulmonary MedicineThe University of Texas MD Anderson Cancer CenterHoustonTXUSA
| | | | | | | | - Martin Gosling
- Enterprise Therapeutics Ltd, Science Park SquareBrightonUK
- School of Life SciencesUniversity of SussexBrightonUK
| |
Collapse
|
11
|
Cardenas EI, Gonzalez R, Breaux K, Da Q, Gutierrez BA, Ramos MA, Cardenas RA, Burns AR, Rumbaut RE, Adachi R. Munc18-2, but not Munc18-1 or Munc18-3, regulates platelet exocytosis, hemostasis, and thrombosis. J Biol Chem 2019; 294:4784-4792. [PMID: 30696774 DOI: 10.1074/jbc.ra118.006922] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 01/24/2019] [Indexed: 12/17/2022] Open
Abstract
Platelet degranulation, a form of regulated exocytosis, is crucial for hemostasis and thrombosis. Exocytosis in platelets is mediated by SNARE proteins, and in most mammalian cells this process is controlled by Munc18 (mammalian homolog of Caenorhabditis elegans uncoordinated gene 18) proteins. Platelets express all Munc18 paralogs (Munc18-1, -2, and -3), but their roles in platelet secretion and function have not been fully characterized. Using Munc18-1, -2, and -3 conditional knockout mice, here we deleted expression of these proteins in platelets and assessed granule exocytosis. We measured products secreted by each type of platelet granule and analyzed EM platelet profiles by design-based stereology. We observed that the removal of Munc18-2 ablates the release of alpha, dense, and lysosomal granules from platelets, but we found no exocytic role for Munc18-1 or -3 in platelets. In vitro, Munc18-2-deficient platelets exhibited defective aggregation at low doses of collagen and impaired thrombus formation under shear stress. In vivo, megakaryocyte-specific Munc18-2 conditional knockout mice had a severe hemostatic defect and prolonged arterial and venous bleeding times. They were also protected against arterial thrombosis in a chemically induced model of arterial injury. Taken together, our results indicate that Munc18-2, but not Munc18-1 or Munc18-3, is essential for regulated exocytosis in platelets and platelet participation in thrombosis and hemostasis.
Collapse
Affiliation(s)
- Eduardo I Cardenas
- From the Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030.,the Escuela de Ingenieria y Ciencias, Instituto Tecnologico de Monterrey, Monterrey, Nuevo Leon 64849, Mexico
| | - Ricardo Gonzalez
- From the Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030.,the Escuela de Ingenieria y Ciencias, Instituto Tecnologico de Monterrey, Monterrey, Nuevo Leon 64849, Mexico
| | - Keegan Breaux
- From the Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030
| | - Qi Da
- the Center for Translational Research on Inflammatory Diseases (CTRID), Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas 77030.,the Department of Medicine, Baylor College of Medicine, Houston, Texas 77030
| | - Berenice A Gutierrez
- From the Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030.,the Escuela de Ingenieria y Ciencias, Instituto Tecnologico de Monterrey, Monterrey, Nuevo Leon 64849, Mexico
| | - Marco A Ramos
- From the Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030
| | - Rodolfo A Cardenas
- From the Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030.,the Escuela de Medicina y Ciencias de la Salud, Instituto Tecnologico de Monterrey, Monterrey, Nuevo León 64710, México, and
| | - Alan R Burns
- the College of Optometry, University of Houston, Houston, Texas 77204
| | - Rolando E Rumbaut
- the Center for Translational Research on Inflammatory Diseases (CTRID), Michael E. DeBakey Veterans Affairs Medical Center, Houston, Texas 77030.,the Department of Medicine, Baylor College of Medicine, Houston, Texas 77030
| | - Roberto Adachi
- From the Department of Pulmonary Medicine, The University of Texas M. D. Anderson Cancer Center, Houston, Texas 77030,
| |
Collapse
|