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Çevik-Aras H, Musa S, Olofsson R, Almståhl A, Almhöjd U. Patients with oral lichen planus display lower levels of salivary acidic glycoproteins than individuals without oral mucosal disease. Clin Oral Investig 2023; 28:2. [PMID: 38114810 PMCID: PMC10730629 DOI: 10.1007/s00784-023-05411-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Accepted: 11/30/2023] [Indexed: 12/21/2023]
Abstract
OBJECTIVES Salivary proteins, acidic glycoproteins, and free calcium might take part in oral mucosal defence against inflammation in oral lichen planus (OLP). The study aimed to investigate whether the levels of sulfated and sialylated glycoproteins, total protein, and free calcium in saliva from patients with OLP differ from those of individuals without oral mucosal diseases. MATERIAL AND METHODS Patients diagnosed with OLP (n = 25) and two control groups without any oral mucosal disease; age- and gender-matched controls (n = 25, 65.6 ± 2.9 years), and younger controls (n = 25, 41.8 ± 2.5 years) were included. Subjective dry mouth (xerostomia) was assessed by asking a single-item question. Chew-stimulated whole saliva was collected to measure sulfated and sialylated glycoproteins by the Alcian Blue method. The total protein was determined spectrophotometrically, and the free calcium measured using an electrode. RESULTS The output of salivary sulfated and sialylated glycoproteins in the OLP group (21.8 ± 2.4 µg/min) was lower than in the age- and gender-matched controls (43.0 ± 2.9 µg/min, p = 0.0002), whereas the total protein and calcium output did not differ between the three groups (p > 0.05). The prevalence of xerostomia was significantly higher in the OLP group compared to both control groups (p = 0.038). CONCLUSIONS Patients with OLP showed a high prevalence of xerostomia and lower levels of salivary acidic type glycoproteins compared to the individuals without oral mucosa disease. CLINICAL RELEVANCE It is relevant to investigate the role of acidic glycoproteins in the pathogenesis of OLP.
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Affiliation(s)
- H Çevik-Aras
- Department of Oral Medicine and Pathology, Institute of Odontology, University of Gothenburg, Gothenburg, Sweden.
- Specialist Clinic for Orofacial Medicine, Northern Älvsborg County Hospital, Public Dental Service, Trollhättan, Region Västra Götaland, Sweden.
| | - Shehed Musa
- Public Dental Service, Gothenburg, Region Västra Götaland, Sweden
| | - Richard Olofsson
- Specialist Clinic for Orofacial Medicine, Public Dental Service, Uddevalla-Trollhättan, Region Västra Götaland, Sweden
| | - Annica Almståhl
- Section 4, -Oral Health, Faculty of Odontology, Malmö University, Malmö, Sweden
- Department of Oral Microbiology and Immunology, Institute of Odontology, University of Gothenburg, Gothenburg, Sweden
| | - Ulrica Almhöjd
- Department of Cariology, Institute of Odontology, University of Gothenburg, Gothenburg, Sweden
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Seregni E, Botti C, Massaron S, Lombardo C, Capobianco A, Bogni A, Bombardieri E. Structure, Function and Gene Expression of Epithelial Mucins. TUMORI JOURNAL 2018; 83:625-32. [PMID: 9267478 DOI: 10.1177/030089169708300301] [Citation(s) in RCA: 65] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In this review the main characteristics, i.e., structure, function and gene expression, of the different mucins are discussed. Mucin-type molecules consist of a core protein moiety (apomucin) where a number of carbohydrate chains are attached to serines and threonines by glycosidic bonds. O-linked carbohydrates form up to 80% of the molecule and the length of the glucidic side chains varies from one to more than 20 residues. At least eight mucin-like genes have been isolated so far, and the main characteristic is the presence of a central domain composed of a variable number of “tandem repeats”. The sequence homology of the central domain among the different members of the mucin-type family is limited, indicating that this internal domain is unique for each mucin. Thanks to the integrated results of genetic, immunological and biochemical studies, it is now possible to identify eight apomucin genes, namely MUC1, MUC2, MUC3, MUC4, MUC5AC, MUC5B, MUC6 and MUC7. MUC1 is the best characterized mucin and it is expressed on the apical surface of most polarized epithelial cells. The MUC1 gene has been cloned and sequenced. The MUC2 gene encodes a typical secretory gel-forming mucin which represents the predominant form in human intestinal and colon tissues. Another intestinal mucin is MUC3. The MUC4, MUC5AC and MUC5B genes have been isolated from a bronchial tissue cDNA library. The MUC4 and MUC5AC genes are mainly expressed in the respiratory tract, in gastric and reproductive mucosa, while MUC5B is highly detectable only in the bronchial glands. The MUC6 gene is expressed by gastric tissue and, recently, MUC7 has been cloned and sequenced using a salivary cDNA library.
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Affiliation(s)
- E Seregni
- Nuclear Medicine Department, Istituto Nazionale per lo Studio e la Cura dei Tumori, Milan
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3
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Exploring the role and diversity of mucins in health and disease with special insight into non-communicable diseases. Glycoconj J 2015; 32:575-613. [PMID: 26239922 DOI: 10.1007/s10719-015-9606-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 06/18/2015] [Indexed: 12/11/2022]
Abstract
Mucins are major glycoprotein components of the mucus that coats the surfaces of cells lining the respiratory, digestive, gastrointestinal and urogenital tracts. They function to protect epithelial cells from infection, dehydration and physical or chemical injury, as well as to aid the passage of materials through a tract i.e., lubrication. They are also implicated in the pathogenesis of benign and malignant diseases of secretory epithelial cells. In Human there are two types of mucins, membrane-bound and secreted that are originated from mucous producing goblet cells localized in the epithelial cell layer or in mucous producing glands and encoded by MUC gene. Mucins belong to a heterogeneous family of high molecular weight proteins composed of a long peptidic chain with a large number of tandem repeats that form the so-called mucin domain. The molecular weight is generally high, ranging between 0.2 and 10 million Dalton and all mucins contain one or more domains which are highly glycosylated. The size and number of repeats vary between mucins and the genetic polymorphism represents number of repeats (VNTR polymorphisms), which means the size of individual mucins can differ substantially between individuals which can be used as markers. In human it is only MUC1 and MUC7 that have mucin domains with less than 40% serine and threonine which in turn could reduce number of PTS domains. Mucins can be considered as powerful two-edged sword, as its normal function protects from unwanted substances and organisms at an arm's length while, malfunction of mucus may be an important factor in human diseases. In this review we have unearthed the current status of different mucin proteins in understanding its role and function in various non-communicable diseases in human with special reference to its organ specific locations. The findings described in this review may be of direct relevance to the major research area in biomedicine with reference to mucin and mucin associated diseases.
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Sudhoff H, Klenke C, Greiner JFW, Müller J, Brotzmann V, Ebmeyer J, Kaltschmidt B, Kaltschmidt C. 1,8-Cineol Reduces Mucus-Production in a Novel Human Ex Vivo Model of Late Rhinosinusitis. PLoS One 2015. [PMID: 26207629 PMCID: PMC4514714 DOI: 10.1371/journal.pone.0133040] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Inflammatory diseases of the respiratory system such as rhinosinusitis, chronic obstructive pulmonary disease, or bronchial asthma are strongly associated with overproduction and hypersecretion of mucus lining the epithelial airway surface. 1,8-cineol, the active ingredient of the pharmaceutical drug Soledum, is commonly applied for treating such inflammatory airway diseases. However, its potential effects on mucus overproduction still remain unclear.In the present study, we successfully established ex vivo cultures of human nasal turbinate slices to investigate the effects of 1,8-cineol on mucus hypersecretion in experimentally induced rhinosinusitis. The presence of acetyl-α-tubulin-positive cilia confirmed the integrity of the ex vivo cultured epithelium. Mucin-filled goblet cells were also detectable in nasal slice cultures, as revealed by Alcian Blue and Periodic acid-Schiff stainings. Treatment of nasal slice cultures with lipopolysaccharides mimicking bacterial infection as observed during late rhinosinusitis led to a significantly increased number of mucin-filled goblet cells. Notably, the number of mucin-filled goblet cells was found to be significantly decreased after co-treatment with 1,8-cineol. On a molecular level, real time PCR-analysis further showed 1,8-cineol to significantly reduce the expression levels of the mucin genes MUC2 and MUC19 in close association with significantly attenuated NF-κB-activity. In conclusion, we demonstrate for the first time a 1,8-cineol-dependent reduction of mucin-filled goblet cells and MUC2-gene expression associated with an attenuated NF-κB-activity in human nasal slice cultures. Our findings suggest that these effects partially account for the clinical benefits of 1,8-cineol-based therapy during rhinosinusitis. Therefore, topical application of 1,8-cineol may offer a novel therapeutic approach to reduce bacteria-induced mucus hypersecretion.
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Affiliation(s)
- Holger Sudhoff
- Department of Otolaryngology, Head and Neck Surgery, Klinikum Bielefeld, D-33604 Bielefeld, Germany
| | - Christin Klenke
- Department of Otolaryngology, Head and Neck Surgery, Klinikum Bielefeld, D-33604 Bielefeld, Germany
| | - Johannes F. W. Greiner
- Department of Otolaryngology, Head and Neck Surgery, Klinikum Bielefeld, D-33604 Bielefeld, Germany
- Department of Cell Biology, University of Bielefeld, D-33501 Bielefeld, Germany
| | - Janine Müller
- Department of Otolaryngology, Head and Neck Surgery, Klinikum Bielefeld, D-33604 Bielefeld, Germany
- AG Molecular Neurobiology, University of Bielefeld, D-33501 Bielefeld, Germany
| | - Viktoria Brotzmann
- Department of Otolaryngology, Head and Neck Surgery, Klinikum Bielefeld, D-33604 Bielefeld, Germany
- Department of Cell Biology, University of Bielefeld, D-33501 Bielefeld, Germany
| | - Jörg Ebmeyer
- Department of Otolaryngology, Head and Neck Surgery, Klinikum Bielefeld, D-33604 Bielefeld, Germany
| | - Barbara Kaltschmidt
- Department of Cell Biology, University of Bielefeld, D-33501 Bielefeld, Germany
- AG Molecular Neurobiology, University of Bielefeld, D-33501 Bielefeld, Germany
| | - Christian Kaltschmidt
- Department of Cell Biology, University of Bielefeld, D-33501 Bielefeld, Germany
- * E-mail:
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Affiliation(s)
- Sabrina Jahn
- Department
of Materials and
Interfaces, Weizmann Institute of Science, 76100 Rehovot, Israel
| | - Jacob Klein
- Department
of Materials and
Interfaces, Weizmann Institute of Science, 76100 Rehovot, Israel
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Montalbano AM, Albano GD, Anzalone G, Bonanno A, Riccobono L, Di Sano C, Gagliardo R, Siena L, Pieper MP, Gjomarkaj M, Profita M. Cigarette smoke alters non-neuronal cholinergic system components inducing MUC5AC production in the H292 cell line. Eur J Pharmacol 2014; 736:35-43. [PMID: 24797786 DOI: 10.1016/j.ejphar.2014.04.022] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2013] [Revised: 04/11/2014] [Accepted: 04/16/2014] [Indexed: 01/26/2023]
Abstract
Cigarette smoke extract (CSE) affects the expression of Choline Acetyl-Transferase (ChAT), muscarinic acetylcholine receptors, and mucin production in bronchial epithelial cells. Mucin 5AC (MUC5AC), muscarinic acetylcholine receptor M3, ChAT expression, acetylcholine levels and acetylcholine binding were measured in a human pulmonary mucoepidermoid carcinoma cell line (H292) stimulated with CSE. We performed ChAT/RNA interference experiments in H292 cells stimulated with CSE to study the role of ChAT/acetylcholine in MUC5AC production. The effects of Hemicholinium-3 (HCh-3) (50 μM) (a potent and selective choline uptake blocker) and Tiotropium bromide (Spiriva(®)) (100 nM), alone or in combination with Salmeterol (SL) and Fluticasone propionate (FP), were tested in this model. MUC5AC, muscarinic acetylcholine receptor M3, ChAT, acetylcholine expression and acetylcholine binding significantly increased in H292 cells stimulated with CSE (5%) compared to untreated cells. HCh-3 reduced acetylcholine binding and MUC5AC production in H292 cells stimulated with CSE. ChAT/RNA interference eliminated the effect of CSE on MUC5AC production. FP reduced ChAT and acetylcholine binding in unstimulated cells, while showing a partial effect in CSE stimulated cells. SL increased the ChAT expression and acetylcholine binding in H292 cells stimulated with or without CSE. Tiotropium, alone or together with FP and SL, reduced acetylcholine binding and MUC5AC production in H292 cells stimulated with CSE. CSE affects the ChAT/acetylcholine expression, increasing MUC5AC production in H292 cells. Pharmacological treatment with anticholinergic drugs reduces the secretion of MUC5AC generated by autocrine acetylcholine activity in airway epithelial cells.
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Affiliation(s)
- Angela Marina Montalbano
- Institute of Biomedicine and Molecular Immunology "A. Monroy" (IBIM), Italian National Research Council (CNR), Palermo, Italy
| | - Giusy Daniela Albano
- Institute of Biomedicine and Molecular Immunology "A. Monroy" (IBIM), Italian National Research Council (CNR), Palermo, Italy; Dipartimento Biomedico di Medicina Interna e Specialistica (Di.Bi.M.I.S.), Sezione di Pneumologia, University of Palermo, Palermo, Italy
| | - Giulia Anzalone
- Institute of Biomedicine and Molecular Immunology "A. Monroy" (IBIM), Italian National Research Council (CNR), Palermo, Italy
| | - Anna Bonanno
- Institute of Biomedicine and Molecular Immunology "A. Monroy" (IBIM), Italian National Research Council (CNR), Palermo, Italy
| | - Loredana Riccobono
- Institute of Biomedicine and Molecular Immunology "A. Monroy" (IBIM), Italian National Research Council (CNR), Palermo, Italy
| | - Caterina Di Sano
- Institute of Biomedicine and Molecular Immunology "A. Monroy" (IBIM), Italian National Research Council (CNR), Palermo, Italy
| | - Rosalia Gagliardo
- Institute of Biomedicine and Molecular Immunology "A. Monroy" (IBIM), Italian National Research Council (CNR), Palermo, Italy
| | - Liboria Siena
- Institute of Biomedicine and Molecular Immunology "A. Monroy" (IBIM), Italian National Research Council (CNR), Palermo, Italy
| | | | - Mark Gjomarkaj
- Institute of Biomedicine and Molecular Immunology "A. Monroy" (IBIM), Italian National Research Council (CNR), Palermo, Italy
| | - Mirella Profita
- Institute of Biomedicine and Molecular Immunology "A. Monroy" (IBIM), Italian National Research Council (CNR), Palermo, Italy.
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7
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Wang YB, Watts AB, Peters JI, Williams RO. The impact of pulmonary diseases on the fate of inhaled medicines—A review. Int J Pharm 2014; 461:112-28. [DOI: 10.1016/j.ijpharm.2013.11.042] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 11/20/2013] [Accepted: 11/20/2013] [Indexed: 11/30/2022]
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8
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Molecular weight distribution analysis by ultracentrifugation: Adaptation of a new approach for mucins. Carbohydr Polym 2013; 93:178-83. [DOI: 10.1016/j.carbpol.2012.05.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2012] [Revised: 05/01/2012] [Accepted: 05/04/2012] [Indexed: 11/18/2022]
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9
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Lewis A, Jones K, Lewis K, Jones S, Lewis P. Detection of Lewis antigen structural change by FTIR spectroscopy. Carbohydr Polym 2013; 92:1294-301. [DOI: 10.1016/j.carbpol.2012.09.078] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2012] [Revised: 09/24/2012] [Accepted: 09/27/2012] [Indexed: 10/27/2022]
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Harvey NM, Yakubov GE, Stokes JR, Klein J. Normal and Shear Forces between Surfaces Bearing Porcine Gastric Mucin, a High-Molecular-Weight Glycoprotein. Biomacromolecules 2011; 12:1041-50. [DOI: 10.1021/bm101369d] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Neale M. Harvey
- The Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
| | - Gleb E. Yakubov
- Unilever R&D, Colworth Science Park, Bedford MK44 1LQ, United Kingdom
| | - Jason R. Stokes
- Unilever R&D, Colworth Science Park, Bedford MK44 1LQ, United Kingdom
| | - Jacob Klein
- The Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, United Kingdom
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel
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Kim S, Lewis C, Nadel JA. CCL20/CCR6 feedback exaggerates epidermal growth factor receptor-dependent MUC5AC mucin production in human airway epithelial (NCI-H292) cells. THE JOURNAL OF IMMUNOLOGY 2011; 186:3392-400. [PMID: 21300824 DOI: 10.4049/jimmunol.1003377] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Mucous hypersecretion is an important feature of obstructive airway diseases such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis. Multiple stimuli induce mucin production via activation of an epidermal growth factor receptor (EGFR) cascade, but the mechanisms that exaggerate mucin production in obstructive airway diseases remain unknown. In this study, we show that binding of CCL20, a G protein-coupled receptor (GPCR) ligand that is upregulated in the airways of subjects with obstructive airway diseases, to its unique GPCR CCR6 induces MUC5AC mucin production in human airway epithelial (NCI-H292) cells via metalloprotease TNF-α-converting enzyme (TACE)-dependent EGFR activation. We also show that EGFR activation by its potent ligand TGF-α induces reactivation of EGFR via binding of endogenously produced CCL20 to its receptor CCR6 in NCI-H292 cells but not in normal human bronchial epithelial (NHBE) cells, exaggerating mucin production in the NCI-H292 cells. In NCI-H292 cells, TGF-α stimulation induced two phases of EGFR phosphorylation (EGFR-P). The second EGFR-P was TACE-dependent and was responsible for most of the total mucin induced by TGF-α. Binding of endogenously produced CCL20 to CCR6 increased the second EGFR-P and subsequent mucin production induced by TGF-α. In NHBE cells, TGF-α-induced EGFR activation did not lead to significant CCL20 production or to EGFR rephosphorylation, and less mucin was produced. We conclude that NCI-H292 cells but not NHBE cells produce CCL20 in response to EGFR activation, which leads to a second phase of EGFR-P and subsequent exaggerated mucin production. These findings have potentially important therapeutic implications in obstructive airway diseases.
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Affiliation(s)
- Suil Kim
- Cardiovascular Research Institute, University of California San Francisco, San Francisco, CA 94143, USA.
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Localized mucinous bronchioloalveolar carcinoma of the lung: thin-section computed tomography and fluorodeoxyglucose positron emission tomography findings. Jpn J Radiol 2010; 28:251-8. [PMID: 20512541 DOI: 10.1007/s11604-009-0414-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2009] [Accepted: 12/17/2009] [Indexed: 12/19/2022]
Abstract
PURPOSE The aim of this study was to evaluate thinsection computed tomography (CT) and fluorodeoxyglucose positron emission tomography (FDG-PET) findings of localized pulmonary mucinous bronchioloalveolar carcinomas (BACs). METHODS AND MATERIALS From February 2000 to February 2009, there were seven patients with pulmonary localized mucinous BACs that were pathologically confirmed in the surgical specimens. Their CT findings were assessed regarding location, extent (percent) of groundglass opacity (GGO), margin characteristics, and the presence of air-containing spaces and contractive changes. We evaluated the presence of the "angiogram sign" in the patients who underwent enhanced CT. The maximum standardized uptake value (SUVmax) on FDG-PET was measured in four cases. RESULTS All tumors were located in the lower lobes. The percentages of GGOs ranged from 0% to 70% (average 20%). The tumor margins were well defined in five cases and ill-defined in two cases. Air-containing spaces were seen in all cases. Evidence of contractive change was seen in two of the seven cases. The angiogram sign was identified in one of five patients who underwent enhanced CT. The SUVmax on FDG-PET ranged from 0.93 to 1.97 (mean 1.53). CONCLUSION The imaging features of localized mucinous BACs include solid or partly solid attenuation, the presence of air-containing spaces, lack of contractive changes, and lower lobe predominance. Additionally, the SUVmax is markedly low on FDG-PET.
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Kim S, Nadel JA. Fibrinogen binding to ICAM-1 promotes EGFR-dependent mucin production in human airway epithelial cells. Am J Physiol Lung Cell Mol Physiol 2009; 297:L174-83. [PMID: 19429776 DOI: 10.1152/ajplung.00032.2009] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Mucous hypersecretion is a serious feature of chronic airway diseases such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis. Although mucins are produced via activation of an EGF receptor (EGFR) signaling cascade, the mechanisms leading to exaggerated mucin production in mucous hypersecretory diseases are unknown. Because expression of ICAM-1 and of the ICAM-1 ligand fibrinogen is increased in the airways of subjects with mucous hypersecretory diseases, we hypothesized that fibrinogen binding to ICAM-1 could increase EGFR-dependent mucin production in human airway (NCI-H292) epithelial cells. Consistent with this hypothesis, we found that an ICAM-1 neutralizing antibody and an ICAM-1(8-22) peptide that binds fibrinogen decreased mucin production induced by the EGFR ligand transforming growth factor (TGF)-alpha dose-dependently. Exogenous fibrinogen and a fibrinogen(117-133) peptide that binds ICAM-1 rescued mucin production in cells treated with the ICAM-1(8-22) peptide. Surprisingly, the ICAM-1(8-22) peptide increased EGFR phosphotyrosine and phospho-ERK1/2 in cells treated with TGF-alpha. The ICAM-1(8-22) peptide-induced increases in EGFR phosphotyrosine and phospho-ERK1/2 were prevented by exogenous fibrinogen, by the fibrinogen(117-133) peptide, and by selective inhibitors of phospholipase C (PLC), protein kinase C (PKC)-alpha/beta, and metalloproteases. These results suggest that fibrinogen binding to ICAM-1 promotes mucin production by decreasing TGF-alpha-induced EGFR and ERK1/2 activation and that the fibrinogen-ICAM-1-dependent decrease in EGFR and ERK1/2 activation occurs via inhibition of an early positive feedback pathway involving PLC- and PKC-alpha/beta-dependent metalloprotease activation and subsequent metalloprotease-dependent EGFR reactivation.
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Affiliation(s)
- Suil Kim
- Department of Medicine, Cardiovascular Research Institute, University of California,San Francisco, California 94143-0130, USA.
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Kirkham S, Kolsum U, Rousseau K, Singh D, Vestbo J, Thornton DJ. MUC5B is the major mucin in the gel phase of sputum in chronic obstructive pulmonary disease. Am J Respir Crit Care Med 2008; 178:1033-9. [PMID: 18776153 PMCID: PMC2643221 DOI: 10.1164/rccm.200803-391oc] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2008] [Accepted: 09/04/2008] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Overproduction of mucus is a contributory factor in the progression of chronic obstructive pulmonary disease (COPD). The polymeric mucins are major macromolecules in the secretion. Therefore, we hypothesized that the polymeric mucin composition or properties may be different in the sputum from individuals with COPD and smokers without airflow obstruction. OBJECTIVES To determine the major polymeric mucins in COPD sputum and whether these are different in the sputum from individuals with COPD compared with that from smokers without airflow obstruction. METHODS The polymeric mucin composition of sputum from patients with COPD and smokers without airflow obstruction was analyzed by Western blotting analysis. The tissue localization of the mucins was determined by immunohistochemistry, and their size distribution was analyzed by rate-zonal centrifugation. MEASUREMENTS AND MAIN RESULTS MUC5AC and MUC5B were the major mucins. MUC5AC was the predominant mucin in the smoker group, whereas MUC5B was more abundant from the patients with COPD, with a significant difference in the ratio of MUC5B to MUC5AC (P = 0.004); this ratio was correlated with FEV(1) in the COPD group (r = 0.63; P = 0.01). The lower-charged glycosylated form of MUC5B was more predominant in COPD (P = 0.012). No significant associations were observed with respect to sex, age, or pack-year history. In both groups, MUC5AC was produced by surface epithelial cells and MUC5B by submucosal gland cells. Finally, there was a shift toward smaller mucins in the COPD group. CONCLUSIONS Our data indicate that there are differences in mucin amounts and properties between smokers with and without COPD. Further studies are needed to examine how this may impact disease progression.
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Affiliation(s)
- Sara Kirkham
- 1Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
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Thornton DJ, Rousseau K, McGuckin MA. Structure and function of the polymeric mucins in airways mucus. Annu Rev Physiol 2008; 70:459-86. [PMID: 17850213 DOI: 10.1146/annurev.physiol.70.113006.100702] [Citation(s) in RCA: 590] [Impact Index Per Article: 36.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The airways mucus gel performs a critical function in defending the respiratory tract against pathogenic and environmental challenges. In normal physiology, the secreted mucins, in particular the polymeric mucins MUC5AC and MUC5B, provide the organizing framework of the airways mucus gel and are major contributors to its rheological properties. However, overproduction of mucins is an important factor in the morbidity and mortality of chronic airways disease (e.g., asthma, cystic fibrosis, and chronic obstructive pulmonary disease). The roles of these enormous, multifunctional, O-linked glycoproteins in health and disease are discussed.
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Affiliation(s)
- David J Thornton
- Wellcome Trust Center for Cell Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, United Kingdom.
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Rousseau K, Byrne C, Griesinger G, Leung A, Chung A, Hill AS, Swallow DM. Allelic association and recombination hotspots in the mucin gene (MUC) complex on chromosome 11p15.5. Ann Hum Genet 2007; 71:561-9. [PMID: 17535267 DOI: 10.1111/j.1469-1809.2007.00374.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A family of four highly polymorphic genes encoding secreted gel forming mucins is located in the middle of a recombination rich region of the short arm of chromosome 11 (11p15.5; tel MUC6-MUC2-MUC5AC-MUC5B cen; approx. 400 kb). These genes are of interest as risk factors for inflammatory diseases of the epithelia, and we have for example reported association of a VNTR polymorphism of the major mucin domain of MUC2 with asthma, despite the fact that MUC2 is not a major respiratory mucin. To understand the significance of this and other mucin gene associations it is important to describe the patterns of linkage disequilibrium (LD) across this chromosomal region, which is still incomplete on HapMap and the UCSC Golden Path sequence. Our previous studies on the 40 core CEPH families provided direct evidence for several recombination events within the immediate region of the gene complex. This study examines these recombination events in more detail, and also the patterns of LD across the gene complex. We refine the location of the breakpoints, and the combined data suggest two probable recombination hotspots. Three breakpoints are located between MUC6 and MUC2: there is no association between MUC6 and MUC2, and the data collected here, combined with that publicly available, maps a hotspot to a region of 4 kb. The other recombinants map between MUC2 and intron 8 of MUC5B. Relatively strong LD is detected between MUC2 and MUC5AC, and although 10/70 of the chromosomes tested shared a common haplotype, which extends from MUC2 to MUC5B, statistically significant association was not detected between MUC2 and the markers tested in MUC5B. We discuss the possibility that the previously reported association between MUC2 and asthma is most likely attributable to association with functional variation in MUC5AC, which encodes one of the two major mucins expressed in both healthy and diseased airways.
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Affiliation(s)
- K Rousseau
- The Galton Laboratory, Department of Biology, University College London, Wolfson House, 4 Stephenson Way, London, NW1 2HE, UK
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17
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Rousseau K, Kirkham S, McKane S, Newton R, Clegg P, Thornton DJ. Muc5b and Muc5ac are the major oligomeric mucins in equine airway mucus. Am J Physiol Lung Cell Mol Physiol 2007; 292:L1396-404. [PMID: 17293373 DOI: 10.1152/ajplung.00444.2006] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Horses frequently suffer from respiratory diseases, which, irrespective of etiology, are often associated with airway mucus accumulation. Studies on human airways have shown that the key structural components of the mucus layer are oligomeric mucins, which can undergo changes of expression and properties in disease. However, there is little information on these gel-forming glycoproteins in horse airways mucus. Therefore, the aims of this study were to isolate equine airways oligomeric mucins, characterize their macromolecular properties, and identify their gene products. To this end, pooled tracheal washes, collected from healthy horses and horses suffering from respiratory diseases, were solubilized with 6 M guanidinium chloride (GdmCl). The oligomeric mucins were purified by density gradient centrifugation followed by size exclusion chromatography. Biochemical and biophysical analyses showed the mucins were stiffened random coils in solution that were polydisperse in size (M(r) = 6-20 MDa, average M(r) = 14 MDa) and comprised of disulfide-linked subunits (average M(r) = 7 MDa). Agarose gel electrophoresis showed that the pooled mucus sample contained at least two populations of oligomeric mucins. Electrospray ionization tandem mass spectrometry of tryptic digests of the unfractionated mucin preparation showed that the oligomeric mucins Muc5b and Muc5ac were present. In summary, we have shown that equine airways mucus is a mixture of Muc5b and Muc5ac mucins that have a similar macromolecular organization to their human counterparts. This study will form the basis for future studies to analyze the contribution of these two mucins to equine airways pathology associated with mucus accumulation.
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Affiliation(s)
- Karine Rousseau
- Wellcome Trust Centre for Cell-Matrix Research, Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
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18
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Henke MO, John G, Germann M, Lindemann H, Rubin BK. MUC5AC and MUC5B mucins increase in cystic fibrosis airway secretions during pulmonary exacerbation. Am J Respir Crit Care Med 2007; 175:816-21. [PMID: 17255563 DOI: 10.1164/rccm.200607-1011oc] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RATIONALE Cystic fibrosis (CF) is believed to be associated with mucus hypersecretion; thus, the principal airway gel-forming mucins, MUC5AC and MUC5B, are also expected to be increased relative to non-CF secretions. However, we have shown that these mucins are decreased during stable CF disease. OBJECTIVES In this study, we determine if these mucins increase during a pulmonary exacerbation of CF. METHODS Expectorated sputum was collected from 11 adults with CF during stable disease and then during a pulmonary exacerbation and from 12 healthy control subjects. MUC5AC and MUC5B proteins were measured by Western blot. DNA content was measured using microfluorimetry. RESULTS MUC5AC protein increased by 908% and MUC5B by 59% (p < 0.05 for both) during an exacerbation compared with periods of stable disease. During stable disease, the vol/vol quantity of MUC5AC protein was 89% less than normal mucus, and the mucin-associated sugars, measured using a lectin binding assay, were 46% less compared with normal mucus. The concentration of DNA in CF sputum did not increase during an exacerbation. CONCLUSIONS During a CF exacerbation, concentration of secreted mucin increased to the amount found in mucus from normal subjects, suggesting that the capacity to secrete mucin in response to an infection or inflammatory stimulus is preserved in CF airways. This might help to protect the airway from injury.
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Affiliation(s)
- Markus O Henke
- Philipps-University Marburg, Department of Pulmonary Medicine, Baldingerstrasse 1, 35043 Marburg, Germany.
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19
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Rogers DF. The role of airway secretions in COPD: pathophysiology, epidemiology and pharmacotherapeutic options. COPD 2007; 2:341-53. [PMID: 17146999 DOI: 10.1080/15412550500218098] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Often considered an aggravating but otherwise benign component of chronic obstructive pulmonary disease (COPD), airway mucus hypersecretion is now recognised as a potential risk factor for an accelerated loss of lung function in COPD and is a key pathophysiological feature in many patients, particularly those prone to respiratory tract infection. Consequently, it is important to develop drugs that inhibit mucus hypersecretion in these susceptible patients. Conventional therapy including anticholinergics, beta2-adrenoceoptor agonists, alone or in combination with corticosteroids, mucolytics and macrolide antibiotics are not entirely or consistently effective in inhibiting airway mucus hypersecretion in COPD. Novel pharmacotherapeutic targets are being investigated, including inhibitors of nerve activity (e.g., BK(Ca) channel activators), tachykinin receptor antagonists, epoxygenase inducers (e.g., benzafibrate), inhibitors of mucin exocytosis (e.g., anti-MARCKS peptide and Munc-18B blockers), inhibitors of mucin synthesis and goblet cell hyperplasia (e.g., EGF receptor tyrosine kinase inhibitors, p38 MAP kinase inhibitors, MEK/ERK inhibitors, hCACL2 blockers and retinoic acid receptor-alpha antagonists), inducers of goblet cell apoptosis (e.g., Bax inducers or Bcl-2 inhibitors), and purinoceptor P(2Y2) antagonists to inhibit mucin secretion or P(2Y2) agonists to hydrate secretions. However, real and theoretical differences delineate the mucus hypersecretory phenotype in COPD from that in other hypersecretory diseases of the airways. More information is required on these differences to identify therapeutic targets pertinent to COPD which, in turn, should lead to rational design of anti-hypersecretory drugs for specific treatment of airway mucus hypersecretion in COPD.
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Affiliation(s)
- Duncan F Rogers
- Thoracic Medicine, National Heart and Lung Institute, Imperial College, London, Dovehouse St., London SW3 6LY, UK.
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20
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Abstract
It has been established that mucus hypersecretion and decreased mucus clearance contribute to the morbidity of chronic obstructive pulmonary disease (COPD). Indeed, the classic definition of chronic bronchitis relies on determining the frequency and duration of sputum expectoration. Despite the well recognized importance of this symptom, there are few therapies routinely used to decrease the sputum production or to improve clearance. There are fewer well conducted clinical trials of existing medications and this has led many regulatory agencies, notably the Food and Drug Administration (FDA), to refuse to register these medications or approve their sale. Similarly, airway clearance devices and chest physical therapy have not been well studied in COPD. Carefully conducted studies of interventions to improve airway clearance, similar to those done in cystic fibrosis (CF), may help us to identify effective therapies and possibly novel diagnostic tests for the management of COPD.
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Affiliation(s)
- Markus O Henke
- Department of Pulmonary Medicine, Philipps-University Marburg, Marburg 35043, Germany
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21
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Abstract
The three-dimensional organization of the tear film, which is produced and drained by the different structures of the ocular adnexa, is essential for maintainance and protection of the ocular surface. This is facilitated by a class of large, highly glycosylated, hydrophilic glycoproteins, the mucins, which are usually expressed in association with a class of peptides having a well-defined, structurally conserved trefoil domain, the mammalian trefoil factor family (TFF) peptides. In this review, the latest information regarding mucin and TFF peptide function and regulation in the human lacrimal system, the tear film and the ocular surface is summarized with regard to mucous epithelia integrity, rheological and antimicrobial properties of the tear film and tear outflow, age-related changes and certain disease states such as dry eye, dacryostenosis and dacryolith formation.
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Affiliation(s)
- Friedrich P Paulsen
- Department of Anatomy and Cell Biology, Martin Luther University Halle-Wittenberg, Grosse Steinstr. 52 06097 Halle (Saale), Germany.
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22
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Pison U, Welte T, Giersig M, Groneberg DA. Nanomedicine for respiratory diseases. Eur J Pharmacol 2006; 533:341-50. [PMID: 16434033 DOI: 10.1016/j.ejphar.2005.12.068] [Citation(s) in RCA: 116] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/13/2005] [Indexed: 11/24/2022]
Abstract
Nanotechnology provides new materials in the nanometer range with many potential applications in clinical medicine and research. Due to their unique size-dependent properties nanomaterial such as nanoparticles offer the possibility to develop both new therapeutic and diagnostic tools. Thus, applied nanotechnology to medical problems--nanomedicine--can offer new concepts that are reviewed. The ability to incorporate drugs into nanosystems displays a new paradigm in pharmacotherapy that could be used for cell-targeted drug delivery. Nontargeted nanosystems such as nanocarriers that are coated with polymers or albumin and solid lipid particles have been used as transporter in vivo. However, nowadays drugs can be coupled to nanocarriers that are specific for cells and/or organs. Thus, drugs that are either trapped within the carriers or deposited in subsurface oil layers could be specifically delivered to organs, tumors and cells. These strategies can be used to concentrate drugs in selected target tissues thus minimizing systemic side effects and toxicity. In addition to these therapeutic options, nanoparticle-based "molecular" imaging displays a field in which this new technology has set the stage for an evolutionary leap in diagnostic imaging. Based on the recent progress in nanobiotechnology there is potential for nanoparticles and -systems to become useful tools as therapeutic and diagnostic tools in the near future.
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Affiliation(s)
- Ulrich Pison
- Department of Anesthesiology and Intensive Care Medicine, Charité Universitätsmedizin Berlin, D-13353 Berlin, Germany.
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23
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Abstract
This review focuses on the role and regulation of mucin glycoproteins (mucins) in airway health and disease. Mucins are highly glycosylated macromolecules (> or =50% carbohydrate, wt/wt). MUC protein backbones are characterized by numerous tandem repeats that contain proline and are high in serine and/or threonine residues, the sites of O-glycosylation. Secretory and membrane-tethered mucins contribute to mucociliary defense, an innate immune defense system that protects the airways against pathogens and environmental toxins. Inflammatory/immune response mediators and the overproduction of mucus characterize chronic airway diseases: asthma, chronic obstructive pulmonary diseases (COPD), or cystic fibrosis (CF). Specific inflammatory/immune response mediators can activate mucin gene regulation and airway remodeling, including goblet cell hyperplasia (GCH). These processes sustain airway mucin overproduction and contribute to airway obstruction by mucus and therefore to the high morbidity and mortality associated with these diseases. Importantly, mucin overproduction and GCH, although linked, are not synonymous and may follow from different signaling and gene regulatory pathways. In section i, structure, expression, and localization of the 18 human MUC genes and MUC gene products having tandem repeat domains and the specificity and application of MUC-specific antibodies that identify mucin gene products in airway tissues, cells, and secretions are overviewed. Mucin overproduction in chronic airway diseases and secretory cell metaplasia in animal model systems are reviewed in section ii and addressed in disease-specific subsections on asthma, COPD, and CF. Information on regulation of mucin genes by inflammatory/immune response mediators is summarized in section iii. In section iv, deficiencies in understanding the functional roles of mucins at the molecular level are identified as areas for further investigations that will impact on airway health and disease. The underlying premise is that understanding the pathways and processes that lead to mucus overproduction in specific airway diseases will allow circumvention or amelioration of these processes.
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Affiliation(s)
- Mary Callaghan Rose
- Research Center for Genetic Medicine, Room 5700, Children's National Medical Center, 111 Michigan Avenue NW, Washington, DC 20010, USA.
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24
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Rogers DF. Mucociliary dysfunction in COPD: effect of current pharmacotherapeutic options. Pulm Pharmacol Ther 2005; 18:1-8. [PMID: 15607121 DOI: 10.1016/j.pupt.2004.08.001] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/05/2004] [Revised: 08/10/2004] [Accepted: 08/10/2004] [Indexed: 11/17/2022]
Abstract
Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity and mortality worldwide. COPD comprises multiple components which, as well as a systemic component, include pulmonary inflammation, airway remodelling and mucociliary dysfunction. The latter features contribute to the development of chronic, progressive airflow limitation. The mucociliary dysfunction component of COPD is due to mucus hypersecretion coupled with a decrease in mucus transport, and represents an important pathophysiological feature requiring appropriate treatment. Current international guidelines do not recommend the use of mucolytics in the treatment of stable COPD. In contrast, bronchodilators are central to symptomatic management of COPD, and include beta(2)-adrenoceptor agonists, anti-cholinergics and methylxanthines. Interestingly, long-acting beta(2)-agonists (LABAs), rather than short-acting beta(2)-agonists, have the potential to improve the mucociliary component of COPD, in addition to providing symptomatic treatment by their bronchodilator action. Combination therapy with a LABA and an inhaled corticosteroid has the potential to more fully address the multicomponent nature of COPD by providing important anti-inflammatory activity, which may indirectly further improve mucociliary clearance. Theoretically, anti-cholinergics are likely to have mixed effects on mucociliary function, but clinically these effects have been difficult to demonstrate. Finally, a number of novel targets for the treatment of airway mucociliary dysfunction have been identified, and targeting agents are currently in development.
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Affiliation(s)
- Duncan F Rogers
- Thoracic Medicine, National Heart and Lung Institute, Imperial College London, Dovehouse Street, London SW3 6LY, UK.
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25
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Abstract
Airway mucus hypersecretion is a clinical feature of a number of childhood diseases, including asthma and bronchitis-associated conditions. However, compared with adults, there is relatively scarce information concerning mucus pathophysiology in respiratory diseases in children. The available evidence indicates many similarities between adult and childhood respiratory hypersecretory conditions, including goblet-cell hyperplasia and submucosal gland hypertrophy, and airway mucus plugging in asthma. Consequently, it is likely that treatments that are effective in adults would be effective in children. Numerous therapeutic targets are linked to the pathophysiology of airway mucus hypersecretion in experimental models and adults with respiratory disease. Whether or not these same targets are relevant in children is for the most part unclear. These targets include the inflammatory cells mediating the inflammatory response that generates the hypersecretory phenotype, and highly specific cellular elements such as epidermal growth factor receptor tyrosine kinase and calcium-activated chloride (CACL) channels. Identification of these factors is linked with the development of different classes of pharmacotherapeutic molecules directed at these targets. Compounds with a broader spectrum of anti-inflammatory activity are likely to be more effective than compounds with restricted activity. However, certain highly specific targets, such as human CACL1 channels, appear to be strongly associated with the development of an airway hypersecretory phenotype. Data from current clinical trials in adults with blockers of these specific targets are awaited with great interest. The hope is that, if effective, pediatric trials with these compounds could be initiated with a view to alleviation of the clinical impact of airway mucus hypersecretion in children. A significant challenge to the therapeutic progression of these new compounds is effective delivery to the airways in children, with the research effort into development of new compounds matched by advances in inhaler design.
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Affiliation(s)
- Duncan F Rogers
- Thoracic Medicine, National Heart and Lung Institute, Imperial College London, London, UK.
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26
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Groneberg DA, Peiser C, Dinh QT, Matthias J, Eynott PR, Heppt W, Carlstedt I, Witt C, Fischer A, Chung KF. Distribution of respiratory mucin proteins in human nasal mucosa. Laryngoscope 2003; 113:520-4. [PMID: 12616207 DOI: 10.1097/00005537-200303000-00023] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
OBJECTIVES/HYPOTHESIS The upper respiratory tract is involved in many acute and chronic respiratory tract diseases that present with the symptom of mucus hypersecretion. Mucin genes that encode for the backbone of glycoproteins contribute to the viscoelastic property of airway mucus. We examined the cellular expression and distribution of two major respiratory mucus-forming glycoproteins, MUC5AC and MUC5B, in normal human nasal tissues. METHODS Immunohistochemical analysis using polyclonal antibodies against the mucins MUC5AC and MUC5B was performed in normal human nasal tissues. RESULTS An abundant staining of submucosal mucus gland and epithelial goblet cells for MUC5B was found. Immunohistochemical analysis of MUC5AC showed staining of surface epithelium goblet cells, whereas there was no staining of glandular cells. Comparison of the expression to lower airways revealed a similar pattern of expression of both mucins. CONCLUSIONS The data in the present study demonstrated the localization of the two major respiratory mucin proteins in human nasal mucosa with a similar distribution of expression of MUC5AC and MUC5B in normal upper and lower airways. Mucin protein expression parallels that of mucin messenger RNA expression.
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Affiliation(s)
- David A Groneberg
- Department of Medicine, Charité School of Medicine, Humboldt University, Charité Campus-Virchow, BMFZ Forum 4 Fach 40, Augustenburger Platz 1, D-13353 Berlin, Germany.
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27
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Nordman H, Davies JR, Lindell G, de Bolós C, Real F, Carlstedt I. Gastric MUC5AC and MUC6 are large oligomeric mucins that differ in size, glycosylation and tissue distribution. Biochem J 2002; 364:191-200. [PMID: 11988092 PMCID: PMC1222561 DOI: 10.1042/bj3640191] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Gastric MUC5AC and MUC6 mucins were studied using polyclonal antibodies. Immunohistochemistry showed MUC5AC to originate from the surface epithelium, whereas MUC6 was produced by the glands. Mucins from the surface epithelium or glands of corpus and antrum were purified using CsCl/4M guanidinium chloride density-gradient centrifugation. MUC5AC appeared as two distinct populations at 1.4 and 1.3 g/ml, whereas MUC6, which was enriched in the gland tissue, appeared at 1.45 g/ml. Reactivity with antibodies against the Le(b) structure (where Le represents the Lewis antigen) followed the MUC5AC distribution, whereas antibodies against the Le(y) structure and reactivity with the GlcNAc-selective Solanum tuberosum lectin coincided with MUC6, suggesting that the two mucins are glycosylated differently. Rate-zonal centrifugation of whole mucins and reduced subunits showed that both gastric MUC5AC and MUC6 are oligomeric glycoproteins composed of disulphide-bond linked subunits and that oligomeric MUC5AC was apparently smaller than MUC6. A heterogeneous population of 'low-density' MUC5AC mucins, which were smaller than the 'high-density' ones both before and after reduction, reacted with an antibody against a variable number tandem repeat sequence within MUC5AC, suggesting that they represent precursor forms of this mucin. Following ion-exchange HPLC, both MUC5AC and MUC6 appeared as several distinct populations, probably corresponding to 'glycoforms' of the mucins, the most highly charged of which were found in the gland tissue.
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Affiliation(s)
- Henrik Nordman
- Mucosal Biology Group, Department of Cell and Molecular Biology, Level C13, BMC Lund University, S-221 84, Lund, Sweden
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28
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Groneberg DA, Eynott PR, Lim S, Oates T, Wu R, Carlstedt I, Roberts P, McCann B, Nicholson AG, Harrison BD, Chung KF. Expression of respiratory mucins in fatal status asthmaticus and mild asthma. Histopathology 2002; 40:367-73. [PMID: 11943022 DOI: 10.1046/j.1365-2559.2002.01378.x] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
AIMS The airways of patients with asthma are characterized by chronic inflammatory changes comprising mainly T-cells and eosinophils, and airway remodelling with goblet cell metaplasia and submucosal gland hyperplasia. Mucus hypersecretion is often a marked feature, particularly in status asthmaticus. The matrix of airway sputum consists of high molecular glycoproteins and mucins. In this study, the expression and distribution of the major gel-forming mucins MUC5AC and MUC5B were studied in fatal status asthmaticus tissues and bronchial biopsies of mild asthmatic patients. The effect of inhaled corticosteroids on the expression of these mucins was also investigated. METHODS AND RESULTS Polyclonal antibodies specific for MUC5AC and MUC5B, and a monoclonal antibody for MUC5B were used to stain lung tissues and airway mucosal biopsies obtained from patients who died of status asthmaticus (n=5) and from mild asthmatics (n=4), respectively. Immunohistochemistry for MUC5AC revealed abundant staining of goblet cells situated in the epithelial surface lining and glandular ducts of tissues from patients with fatal asthma. MUC5B immunoreactivity was restricted to mucous cells of submucosal glands and to epithelial cells. In mild asthmatics, large amounts of MUC5B, but not MUC5AC, positive extracellular mucus was found in the airway lumen as plugs, adjacent to the epithelial lining and in the necks of glandular secretory ducts of mild asthmatics. The distribution of MUC5AC and MUC5B in bronchial biopsies of mild asthmatics was similar before and after inhaled steroid treatment. CONCLUSIONS The expression of MUC5AC and MUC5B shares a similar distribution to normal airways in different states of asthma. The distribution is not affected by topical corticosteroid therapy.
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Affiliation(s)
- D A Groneberg
- Thoracic Medicine, National Heart & Lung Institute, Imperial College of Science Technology & Medicine, London, UK
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29
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Taylor-Papadimitriou J, Burchell JM, Plunkett T, Graham R, Correa I, Miles D, Smith M. MUC1 and the immunobiology of cancer. J Mammary Gland Biol Neoplasia 2002; 7:209-21. [PMID: 12463741 DOI: 10.1023/a:1020360121451] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The membrane epithelial mucin MUC1 is expressed at the luminal surface of most simple epithelial cells, but expression is greatly increased at lactation and in most breast carcinomas. The increase in level of expression of MUC1 in breast cancer is accompanied by changes in the profile of glycosyl transferases involved in the synthesis of the O-glycans attached to the MUC1 core protein. The cancer-associated mucin is therefore structurally different from the normal mucin, and expresses novel B cell epitopes. MUC1 antibodies are used for in vivo targeting of breast and ovarian tumors, and there is considerable interest in MUC1 as a possible target antigen for the immunotherapy of breast cancer. The different glycoforms can affect cell interactions differently, depending on whether specific interactions with lectins occur. In the absence of such lectin interactions, the long sialylated and negatively charged molecule can inhibit intercellular interactions between other cell surface molecules. The potential role of the different components of the immune system in MUC1 responses are discussed within the framework of how to develop logical strategies for designing clinical studies.
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Affiliation(s)
- Joyce Taylor-Papadimitriou
- Breast Cancer Biology Group, Cancer Research UK, Floor 3, Thomas Guy House, Guy's Hospital, London SE1 9RT, United Kingdom.
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Groneberg DA, Eynott PR, Oates T, Lim S, Wu R, Carlstedt I, Nicholson AG, Chung KF. Expression of MUC5AC and MUC5B mucins in normal and cystic fibrosis lung. Respir Med 2002; 96:81-6. [PMID: 11860173 DOI: 10.1053/rmed.2001.1221] [Citation(s) in RCA: 126] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Hypersecretion of airway mucus is a characteristic feature of chronic airway diseases like cystic fibrosis (CF) and leads via impairment of the muco-ciliary clearance and bacterial superinfection to respiratory failure. The major components of the mucus matrix forming family of mucins in the airways are MUC5AC and MUC5B. To investigate the expression of these glycoproteins in CF, immunohistochemistry was carried out on trachea, bronchi and peripheral lung obtained from CF patients and compared to normal lung tissues. MUC5AC immunohistochemistry demonstrated signals in goblet cells of the epithelial lining. Also, goblet cells inside glandular secretory ducts revealed MUC5AC-positive staining. In comparison to those from normal subjects, CF sections were characterized by inflammatory changes and goblet cell hyperplasia, resulting in increased numbers of MUC5AC-positive cells. Immunohistochemical staining for MUC5B showed abundant staining of submucosal glands and epithelial goblet cells. Inside the glands, the immunoreactivity was restricted to glandular mucous cells. MUC5AC and MUC5B are expressed in the same histological pattern in CF compared to normal tissues with an increase of MUC5AC-positive cells due to goblet cell hyper- and metaplasia.
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Affiliation(s)
- D A Groneberg
- Thoracic Medicine, National Heart and Lung Institute, Imperial College of Science Technology and Medicine, London, UK
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31
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Abstract
Aggregation phenomena in aqueous solutions of purified human tracheobronchial mucin have been studied by rheological methods, steady-state fluorescence, quasielastic light scattering, and spin probe techniques. At temperatures below 30 degrees C and concentrations above 15 mg/mL and in the absence of chaotropic agents, mucin solutions are viscoelastic gels. A gel-sol transition is observed at temperatures above 30 degrees C that is manifested by the diminishing storage modulus and a loss tangent above unity throughout the studied frequency range of the oscillatory shear. No decline in the mucin molecular weight is observed by size-exclusion chromatography above 30 degrees C in the absence of redox agents or proteolytic enzymes. Aggregation of hydrophobic protein segments of the mucin chains at 37 degrees C is indicated by QELS experiments. The decreasing polarity of the microenvironment of pyrene solubilized into mucin solutions at temperatures above 30 degrees C, concomitant with the gel-sol transition, shows the hydrophobicity of the formed aggregates. ESR spectra of the fatty acid spin probe, 16-doxylstearic acid indicate that the aggregate-aqueous interface becomes more developed at elevated temperatures.
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Affiliation(s)
- L E Bromberg
- Department of Physics, Center for Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
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32
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Svitacheva N, Davies JR. Mucin biosynthesis and secretion in tracheal epithelial cells in primary culture. Biochem J 2001; 353:23-32. [PMID: 11115395 PMCID: PMC1221539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Density-gradient centrifugation of bovine tracheal epithelial cell extracts revealed a 'high-density' (1.48 g/ml) sialic-acid-rich population as well as a 'low-density' (1.42 g/ml) one that reacted more strongly with a periodate-Schiff (PAS) assay. The sialic-acid-rich mucins were oligomeric molecules containing disulphide- bond-linked subunits and large glycosylated domains, whereas the PAS-reactive component seemed to be smaller and 'monomeric'. Only the 'high-density' population was secreted from cells cultured for 5 days on plastic or a collagen type 1, Matrigel or Vitrogen substrate. Release was less from cells grown on plastic than from those on a substrate and the amount was unaffected by increasing the thickness of the collagen layer. For cells grown on collagen, the amount of the sialic-acid-rich mucin increased over 10 days, whereas the PAS-reactive component was largely absent after 24 h, which was consistent with an initial release of stored PAS-reactive molecules and synthesis of the sialic-acid-rich mucins de novo. Both [(3)H]proline and [(35)S]sulphate were poorly incorporated into mucins detected with the chemical assays but molecules with a higher buoyant density than that of either of the previously identified species were labelled with [(35)S]sulphate. The [(35)S]sulphate-labelled material yielded large trypsin-resistant fragments and contained O-linked glycans but was not affected by digestion with chondroitin ABC lyase or heparan sulphate lyase, suggesting that it is a mucin rather than a proteoglycan. [(35)S]Sulphate is thus a poor marker for the major oligomeric mucins produced by bovine tracheal epithelial cells but the radiolabel is incorporated into a heavily labelled mucin-like component.
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Affiliation(s)
- N Svitacheva
- Department of Cell and Molecular Biology, Section for Molecular Pathogenesis, Lund University, P.O. Box 94, S-22100 Lund, Sweden
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Shin CY, Lee WJ, Kim DJ, Park CS, Choi EY, Ko KH. Cross-species immunoreactivity of airway mucin as revealed by monoclonal antibodies directed against mucins from human, hamster, and rat. Hybridoma (Larchmt) 2000; 19:397-405. [PMID: 11128029 DOI: 10.1089/02724570050198910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Airway mucin plays crucial role in host-defense and has been implicated in pathophysiology of various airway diseases including asthma and cystic fibrosis. The analysis of airway mucin has been hampered mostly by the lack of specific and efficient methods for the detection of mucin. Recent production of antibodies against airway mucin from several species and also the development of immunoassay procedures make it more efficient to study the airway mucin. However, the cross-species immunoreactivity of antibodies against airway mucin has not been clearly demonstrated and this prompted us to investigate the cross-species immunoreactivity of monoclonal antibodies against human (HM02), hamster (HTA), and rat airway mucin (RT03), which is three most widely used species in the study of mucin. All the monoclonal antibodies (MAbs) used in this study is IgM isotype and recognizes N-acetyl-galactosamine-linked carbohydrate core or backbone portion of airway mucin. In enzyme-linked immunoadsorbent assay (ELISA), Western blot, immunoprecipitation, and immunohistochemical staining experiments, it was demonstrated that human and hamster airway mucin showed strong cross-species immunoreactivity. However, rat airway mucin did not show any cross-species immunoreactivity against human and hamster airway mucin. Endotoxin-induced secretory cell metaplasia and hence the increase in mucin release from hamster airway mucin could be detected with antibodies against hamster and human airway mucin in vivo and in vitro. However, the same increase from rat airway could only be detected with antibody against rat airway mucin but not with antibodies against human and hamster airway mucin. In addition, the increase in mucin release from asthmatic patients could be detected with antibodies against human and hamster airway mucin but not with the antibody against rat airway mucin. The data from the present study implicates that the carbohydrate chain of human and hamster airway mucin, but not that of rat airway mucin, share common antigenic structure. In case of the interspecies use of the antibodies against airway mucin, it would be more desirable to clearly identify the cross-species immunoreactivity otherwise might lead to erroneous results.
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Affiliation(s)
- C Y Shin
- Department of Pharmacology, College of Pharmacy, Seoul National University, Korea
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Sheehan JK, Brazeau C, Kutay S, Pigeon H, Kirkham S, Howard M, Thornton DJ. Physical characterization of the MUC5AC mucin: a highly oligomeric glycoprotein whether isolated from cell culture or in vivo from respiratory mucous secretions. Biochem J 2000; 347 Pt 1:37-44. [PMID: 10727399 PMCID: PMC1220928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
We have isolated the high-M(r) mucins from growth medium of the early stage of an HT-29 cell culture by gel chromatography and isopycnic density gradient centrifugation. The mucins (buoyant density 1.34-1.44 g/ml) were reactive with an anti-peptide antiserum (MAN-5ACI) raised against a sequence from within the MUC5AC mucin. Similar antisera raised against the MUC2 and MUC5B mucins were not reactive. The MUC5AC reduced-mucin subunits exhibited a homogeneous charge distribution on anion-exchange chromatography, but appeared as two bands, one major and one more minor, after agarose gel electrophoresis. The unreduced mucins had an average M(r) in excess of 40 MDa and were visualized in the electron microscope as large, fine filamentous threads (many microns in length) that after reduction were greatly reduced in size (number average length 570 nm). Agarose gel electrophoresis of unreduced MUC5AC mucins identified a major band just entering the gel with evidence of a 'ladder' of faster-migrating minor bands. Partial reduction of the mucins increased the proportion of the faster bands and at least 16 could be discriminated. M(r) measurements showed that these bands differed by single monomer units. The mucins behaved as very stiff extended structures in solution and this characteristic might explain the poor separation of different-sized oligomers in sedimentation-rate experiments. The cell-culture mucin preparation had similar characteristics of charge and buoyant density to MUC5AC mucins from respiratory secretions in vivo. In addition the MUC5AC mucin from respiratory tract secretions exhibited similar behaviour, reduced and unreduced on agarose gel electrophoresis, indicating that the mucin has a similar molecular phenotype in vivo and in vitro.
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Affiliation(s)
- J K Sheehan
- The Wellcome Trust Centre for Cell-Matrix Research, Division of Biochemistry, School of Biological Sciences, 2.205, Stopford Building, University of Manchester, Manchester M13 9PT, U.K.
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35
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Davies JR, Svitacheva N, Lannefors L, Kornfält R, Carlstedt I. Identification of MUC5B, MUC5AC and small amounts of MUC2 mucins in cystic fibrosis airway secretions. Biochem J 1999; 344 Pt 2:321-30. [PMID: 10567212 PMCID: PMC1220647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
To investigate the genetic identities of the mucins secreted in cystic fibrosis (CF) airways, sputum was collected from five individuals. Samples were separated into gel and sol phases by high-speed centrifugation and the gel phase was extracted in 6 M guanidinium chloride. The 'insoluble' residue remaining after extraction of the gel phase was brought into solution by reduction/alkylation. Density-gradient centrifugation in CsCl revealed polydisperse distributions of sialic acid-containing mucins in the gel phase, insoluble residue and sol phase fractions and the degree of variation between the different individuals was low. Antibodies recognizing MUC5AC and MUC5B identified these mucins in each of the fractions. MUC2, however, was present only as a component of the insoluble residue from the gel which accounted for less than 4% by mass of the total mucins. MUC5B and MUC5AC from the gel phase were large oligomeric species composed of disulphide-bond linked subunits and MUC5B was present as two populations with different charge densities which are likely to correspond to MUC5B 'glycoforms'. The sol phase contained, in addition to MUC5AC and MUC5B, mainly smaller mucins which did not react with the antisera and which were probably degraded. MUC5AC appeared to be enriched in the sol, suggesting that this mucin may be more susceptible to proteolytic degradation than MUC5B. The mucins present in sputum remained broadly similar during acute exacerbation and following antibiotic treatment, although the relative amount of an acidic MUC5B glycoform was decreased during infection.
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Affiliation(s)
- J R Davies
- Mucosal Biology Group, Department of Cell and Molecular Biology, Section for Molecular Pathogenesis, Lund University, S-221 00 Lund, Sweden.
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Herrmann A, Davies JR, Lindell G, Mårtensson S, Packer NH, Swallow DM, Carlstedt I. Studies on the "insoluble" glycoprotein complex from human colon. Identification of reduction-insensitive MUC2 oligomers and C-terminal cleavage. J Biol Chem 1999; 274:15828-36. [PMID: 10336486 DOI: 10.1074/jbc.274.22.15828] [Citation(s) in RCA: 115] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The "insoluble" glycoprotein complex was isolated from human colonic tissue and mucin subunits were prepared following reduction. Antibodies raised against peptide sequences within MUC2 revealed that virtually all of this mucin occurs in the insoluble glycoprotein complex. In addition, reduction released a 120-kDa C-terminal MUC2 fragment, showing that proteolytic cleavage in this domain may occur and leave the fragment attached to the complex via disulfide bonds. The variable number tandem repeat region and the irregular repeat domain were isolated after trypsin digestion and shown to have molecular weights of 930,000 and 180,000, respectively, suggesting a molecular weight for the entire MUC2 monomer of approximately 1.5 million. Gel chromatography and agarose gel electrophoresis revealed several populations of MUC2 subunits, and analytical ultracentrifugation showed that these have molecular weights on the order of 2 million, 4 million, and 5 million, corresponding to monomers, dimers, and trimers, respectively. Agarose gel electrophoresis of subunits from individuals expressing both a "long" and a "short" MUC2 allele revealed a larger number of populations, consistent with the presence of short and long monomers and oligomers arising from permutations of the two types of monomers. In addition to disulfide bonds, MUC2 monomers are apparently joined by a "novel," reduction-insensitive bond.
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Affiliation(s)
- A Herrmann
- Mucosal Biology Group, Department of Cell and Molecular Biology, Section for Molecular Pathogenesis, Lund University, P. O. Box 94, 221 00 Lund, Sweden
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Borchers MT, Carty MP, Leikauf GD. Regulation of human airway mucins by acrolein and inflammatory mediators. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:L549-55. [PMID: 10198352 DOI: 10.1152/ajplung.1999.276.4.l549] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Bronchitis, asthma, and cystic fibrosis, marked by inflammation and mucus hypersecretion, can be caused or exacerbated by airway pathogens or irritants including acrolein, an aldehyde present in tobacco smoke. To determine whether acrolein and inflammatory mediators alter mucin gene expression, steady-state mRNA levels of two airway mucins, MUC5AC and MUC5B, were measured (by RT-PCR) in human lung carcinoma cells (NCI-H292). MUC5AC mRNA levels increased after >/=0.01 nM acrolein, 10 microM prostaglandin E2 or 15-hydroxyeicosatetraenoic acid, 1.0 nM tumor necrosis factor-alpha (TNF-alpha), or 10 nM phorbol 12-myristate 13-acetate (a protein kinase C activator). In contrast, MUC5B mRNA levels, although easily detected, were unaffected by these agonists, suggesting that irritants and associated inflammatory mediators increase mucin biosynthesis by inducing MUC5AC message levels, whereas MUC5B is constitutively expressed. When transcription was inhibited, TNF-alpha exposure increased MUC5AC message half-life compared with control level, suggesting that transcript stabilization is a major mechanism controlling increased MUC5AC message levels. Together, these findings imply that irritants like acrolein can directly and indirectly (via inflammatory mediators) increase airway mucin transcripts in epithelial cells.
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Affiliation(s)
- M T Borchers
- Department of Environmental Health, University of Cincinnati College of Medicine, Cincinnati, Ohio 45267-0056, USA
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Sheehan JK, Howard M, Richardson PS, Longwill T, Thornton DJ. Physical characterization of a low-charge glycoform of the MUC5B mucin comprising the gel-phase of an asthmatic respiratory mucous plug. Biochem J 1999; 338 ( Pt 2):507-13. [PMID: 10024529 PMCID: PMC1220079] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
We have previously noted that sequential extraction of an asthmatic mucous exudate with 6 M guanidinium chloride yielded a fraction of the mucins that were most resistant to solubilization and of high Mr [Sheehan, Richardson, Fung, Howard and Thornton (1995) Am. J. Respir. Cell Mol. Biol. 13, 748-756]. Here we show that this mucin fraction is dominated (at least 96% of the total) by the low-charge glycoform of the MUC5B gene product. Seen in the electron microscope the mucins appeared mainly as compact 'island' structures composed of linear threads often emanating from globular 'nodes' rather than the discrete linear threads more typical of mucins that we have previously described. The effect of reducing agents was as expected for other gel-forming mucins, i.e. reduced subunits or monomers of Mr 3x10(6)) were produced within 15 min of treatment. Kinetic experiments on the cleavage of the intact mucins with the proteinase trypsin indicated two clear regimes of fragmentation. An initial rapid cleavage generated mucins ranging from Mr=4x10(6) to 30x10(6) that in the electron microscope appeared as polydisperse threads (500-3000 nm in length), similar to normal and other respiratory mucins that we have previously characterized. A subsequent slower fragmentation over many hours yielded a major fragment of Mr 3x10(6) and length 200-600 nm, very similar in size and Mr to the subunits obtained by reduction. The results suggest that the MUC5B mucin is assembled, first into polydisperse linear threads, which are then linked together via a protein-mediated process. This might involve part of the mucin polypeptide or an as yet unidentified protein(s). The high proteinase susceptibility of the linkage suggests that it might be a point of control for mucin size and thus mucus rheology.
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Affiliation(s)
- J K Sheehan
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, School of Biological Sciences, 2.205, Stopford Building, Manchester M13 9PT, UK.
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Savolainen H. Isolation and separation of proteoglycans. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 722:255-62. [PMID: 10068144 DOI: 10.1016/s0378-4347(98)00312-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Proteoglycans contain a polypeptide core and an oligosaccharide chain composed of aminohexoses and uronic acid. The glycan chain is attached to the polypeptide in a bond to serine hydroxyl. The glycan chains may contain up to 200 disaccharide units and the proteoglycan molecular mass ranges from a few thousands to millions. Their physiological functions are related to barriers limiting diffusion across the membranes, articular lubrification, blood coagulation and cellular adhesion. The tissue proteoglycans can be extracted with 4 M guanidine hydrochloride and purified with chromatographic techniques. The soluble proteoglycans can be precipitated with cetylpyridinium chloride, purified by chromatography or by dialysis. All proteoglycan species are amenable to electrophoresis on polyacrylamide gels, and after blotting on polyvinylidene fluoride membranes, they can be stained for glycans. Proteoglycan analyses have shown their value in clinical mucopolysaccharidosis diagnostics, in occupational toxicology and in coagulation studies. Experimental applications include cell adhesion studies in tumor biology, regeneration in neurosciences or maturation of skin and kidneys.
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Affiliation(s)
- H Savolainen
- Institute of Occupational Health Sciences, Lausanne, Switzerland
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Wickström C, Davies JR, Eriksen GV, Veerman EC, Carlstedt I. MUC5B is a major gel-forming, oligomeric mucin from human salivary gland, respiratory tract and endocervix: identification of glycoforms and C-terminal cleavage. Biochem J 1998; 334 ( Pt 3):685-93. [PMID: 9729478 PMCID: PMC1219739 DOI: 10.1042/bj3340685] [Citation(s) in RCA: 232] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Mucins from human whole saliva, as well as from respiratory- and cervical-tract secretions, were subjected to density-gradient centrifugation in CsCl/0.5 M guanidinium chloride. A polydisperse population of MUC5B mucins was demonstrated in all samples using anti-peptide antisera (LUM5B-2, LUM5B-3 and LUM5B-4) raised against sequences within the MUC5B mucin. The sequences recognized by the LUM5B-2 and LUM5B-3 antisera are located within the domains flanking the highly glycosylated regions of MUC5B, and reduction increased the reactivity with these antibodies, suggesting that the epitopes are partially shielded and that these regions are folded and stabilized by disulphide bonds. Rate-zonal centrifugation before and after reduction showed MUC5B to be a large oligomeric mucin composed of disulphide-linked subunits. In saliva and respiratory-tract secretions, populations of MUC5B mucins with different charge densities were identified by ion-exchange HPLC, suggesting the presence of MUC5B 'glycoforms'. In trachea, the F2 monoclonal antibody against the sulpho-Lewis C structure reacted preferentially with the later-to-be-eluted populations. An antibody (LUM5B-4) recognizing a sequence in the C-terminal domain of MUC5B identified, after reduction, the mucin subunits as well as smaller fragments, suggesting that some of the MUC5B mucins are cleaved within the C-terminal domain. Immunohistochemistry revealed that MUC5B is produced by cells dispersed throughout the human submandibular and sublingual glands, in the airway submucosal glands as well as the goblet cells, and in the epithelium and glands of the endocervix. The F2 antibody stained a subpopulation of the MUC5B-producing cells in the airway submucosal glands, suggesting that different cells may produce different glycoforms of MUC5B in this tissue.
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Affiliation(s)
- C Wickström
- Mucosal Biology Group, Department of Cell and Molecular Biology, Section for Molecular Pathogenesis, Lund University, Lund, Sweden
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Eriksen GV, Carlstedt I, Uldbjerg N, Ernst E. Cervical mucins affect the motility of human spermatozoa in vitro. Fertil Steril 1998; 70:350-4. [PMID: 9696233 DOI: 10.1016/s0015-0282(98)00158-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To test the hypothesis that human cervical mucins affect the motility and hyperactivated motility of human spermatozoa. DESIGN SETTING University hospital. PATIENT(S) Healthy donors. INTERVENTION(S) Swim-up sperm fractions of normozoospermic semen samples were incubated in the presence of 0 (control) to 1.3 mg/mL of mucins purified from cervical mucus plugs released during labor. Motility analyses were performed at time 0, and after 0.5, 1, 3, and 7 hours. MAIN OUTCOME MEASURE(S) Sperm kinematic variables recorded by computer-aided sperm analysis. Hyperactivation was defined as linearity <30%, amplitude of lateral head displacement >7.0 microm, and curvilinear velocity >70 microm/s. RESULT(S) A dose-related effect of cervical mucins on sperm motility was found. Mucins at a concentration of 1.3 mg/mL caused an immediate and significant increase in sperm linearity (27%) and straight-line velocity (16%) compared with control samples. During the first 3 hours of incubation, an approximately 25% increase in linearity and straight-line velocity was found; this increase was statistically significant. Effects on the hyperactivation pattern were found as incubation with mucins for 3 and 7 hours significantly reduced the percentage of hyperactivation from 18% to 9%. CONCLUSION(S) Cervical mucins increase the percentage of progressively motile sperm and decrease the percentage of sperm that show hyperactivation.
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Affiliation(s)
- G V Eriksen
- Aarhus University Hospital, University of Aarhus, Denmark.
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Svitacheva N, Hovenberg HW, Davies JR. Biosynthesis of mucins in bovine trachea: identification of the major radiolabelled species. Biochem J 1998; 333 ( Pt 2):449-56. [PMID: 9657987 PMCID: PMC1219604 DOI: 10.1042/bj3330449] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Bovine trachea in organ culture secretes mucus containing a 'high-density' (1.46 g/ml) and a 'low-density' (1.37 g/ml) mucin similar to those identified previously in bovine respiratory secretions [Hovenberg, Carlstedt and Davies (1997) Biochem. J. 321, 117-123]. After pulse-labelling, autoradiography showed uptake of [35S]sulphate by both epithelial goblet cells and submucosal glands, while [3H]proline was mainly incorporated into the ciliated surface epithelial cells. After 24 h of radiolabelling, neither the high- nor the low-density mucin in the secreted mucus gel was heavily radiolabelled with the precursors. In contrast, a population of molecules banding at 1.50 g/ml was heavily radiolabelled with [35S]sulphate. This component was smaller than the high-density mucin from the mucus gel and was insensitive to reduction or digestion with chondroitin ABC lyase or heparan sulphate lyase. The molecules yielded two populations of high-Mr glycopeptides upon trypsin digestion, were sensitive to keratanase and endo-beta-galactosidase digestion and contained O-linked glycans. Extracts of the surface epithelium and submucosal tissue after radiolabelling showed that the high- and low-density mucins in the tissue were also poorly radiolabelled. Thus, under these conditions, the radiolabelled precursors were not effectively incorporated into the large oligomeric mucins but into a high-Mr monomeric species. This study suggests that data obtained in investigations where mucins are radiolabelled and studied without further separation into distinct components may rather reflect the turnover of this 'novel' monomeric species than the large oligomeric mucins.
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Affiliation(s)
- N Svitacheva
- Department of Cell and Molecular Biology, Section for Molecular Pathogenesis, Lund University, Lund, P.O. Box 94, S-22100 Sweden
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Nordman H, Davies JR, Carlstedt I. Mucus glycoproteins from pig gastric mucosa: different mucins are produced by the surface epithelium and the glands. Biochem J 1998; 331 ( Pt 3):687-94. [PMID: 9560293 PMCID: PMC1219406 DOI: 10.1042/bj3310687] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
An antibody (PGM2B) recognizing a pig gastric-mucin apoprotein reacts with the surface epithelium of pig gastric mucosa. Virtually no reactivity was observed over the mucin-producing cells in the glands, which were recognized by the GlcNAc-selective Griffonia simplicifolia II (GSA-II) lectin. Mucins from the glandular tissue of the cardiac region, corpus and antrum were purified using isopycnic density-gradient centrifugation in CsCl/guanidinium chloride. In the cardiac region, two major mucin populations at 1.5 and 1.4 g/ml were identified. The high-density population reacted preferentially with the PGM2B antibody and resembled mucins from the surface epithelium of this region, whereas the low-density population reacted strongly with the GSA-II lectin and appeared to originate from the glands. In the glandular tissue of corpus, a component with strong GSA-II lectin reactivity, which was distinctly different from the surface mucins from this region, was found at 1.4 g/ml, thus resembling the gland component from the cardiac region. Mucins from antrum glandular tissue contained at least two GSA-II lectin-reactive populations banding at 1.5 and 1.4 g/ml, respectively. Gland mucins from all regions were large oligomeric glycoproteins and heterogeneous with respect to charge properties, as shown by using rate-zonal centrifugation and ion-exchange HPLC, respectively. Gel chromatography of mucin glycopeptides showed that gland mucins from antrum and corpus contained significantly longer glycosylated domains than those from the surface mucosa. Thus, mucins from pig gastric glandular tissue comprise a number of large and oligomeric glycoproteins that differ from those from the surface epithelium in buoyant density, apoprotein structure and carbohydrate substitution.
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Affiliation(s)
- H Nordman
- Mucosal Biology Group, Department of Cell and Molecular Biology, Section for Molecular Pathogenesis, Lund University, P.O. Box 94, S-221 00 Lund, Sweden
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Abstract
Mucins are widely distributed in mucous secretion fluids or are associated with plasma membranes. Up to now 9 genes of epithelial mucins have been identified, distributed over five chromosomes. Superposed on the genetic diversity, each type of mucin displays heterogeneity in oligosaccharide composition, including the terminal sugar residues. On top of that there is variation between individuals brought about by blood group antigens. Heterogeneity is further incited by the degree of sulfation. This tremendous structural heterogeneity endows mucin molecules with properties suggestive for a multifunctional role. The major biological function assigned to mucins is still the protection of tissues covered by the mucous gel. Current knowledge on the specific biological functions of the sulfate residues is fragmentary and periphrastic. Glycosylation including sulfation appears to be subject to modification under pathological conditions. There is evidence that sulfation rate-limits bacterial degradation of mucins. Moreover, accumulating data focus towards their involvement in recognition phenomena. Sulfate residues on blood group related structures provoke specific epitopes for selective interaction with microorganisms e.g. Helicobacter pylori. A distinct class of mucins acts as ligands for selectins, crucial in cellular recognition processes like cellular homing of lymphocytes. Whereas in earlier days mucins were only seen as water-binding molecules, protecting the underlying mucosa against harmful agents, the current picture of these molecules is characterized by the selective interaction with their environment, including epithelial-, and endothelial cells and microorganisms, thereby regulating a great number of biological processes. However, the specific role of sulfate remains to be further elucidated.
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Affiliation(s)
- A V Nieuw Amerongen
- Dept. of Oral Biochemistry, Academic Centre for Dentistry Amsterdam (ACTA), The Netherlands
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45
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Nordman H, Davies JR, Herrmann A, Karlsson NG, Hansson GC, Carlstedt I. Mucus glycoproteins from pig gastric mucosa: identification ofdifferent mucin populations from the surface epithelium. Biochem J 1997; 326 ( Pt 3):903-10. [PMID: 9307044 PMCID: PMC1218749 DOI: 10.1042/bj3260903] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pig gastric mucins were isolated from the surface epithelium of the cardiac region, corpus and antrum using density-gradient centrifugation after extraction in 6 M guanidinium chloride. In CsCl/0.5 M guanidinium chloride, mucins solubilized from the cardiac region appeared as a broad unimodal band at 1.52 g/ml whereas those from the corpus and antrum occurred as high- and low-density populations at 1.50 and 1.45 g/ml respectively. High-iron diamine reacted more strongly with the cardiac mucins and the high-density populations from corpus and antrum than with the two low-density ones. In keeping with this, approx. 60% of the oligosaccharides from the former mucins and 20% from the latter contained sulphate. All surface epithelial cells of the cardiac region stained with high-iron diamine, whereas in the corpus only the epithelium in the bottom of the pits reacted, suggesting that the high-density population from this region originates from these cells. Mucins from all regions were composed of subunits, each containing highly glycosylated domains. The mucins from the cardiac region were larger than those from the corpus and antrum, and reduced subunits as well as high-molecular-mass glycopeptides from the cardiac mucins were larger than the corresponding fragments from the other regions. Ion-exchange HPLC showed that reduced subunits from the cardiac mucins and the high-density populations from the corpus and antrum were more 'acidic' than reduced subunits from the two low-density ones. All mucins contained a 'neutral'fraction, in particular those from the antrum. Pig gastric mucus thus contains a number of distinctly different mucin populations varying in buoyant density, size, 'acidity', glycosylation, sulphation and tissue origin.
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Affiliation(s)
- H Nordman
- Department of Cell and Molecular Biology, Section for Molecular Pathogenesis, Lund University, P.O. Box 94, S-221 00 Lund, Sweden
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Hovenberg HW, Carlstedt I, Davies JR. Mucus glycoproteins in bovine trachea: identification of the major mucin populations in respiratory secretions and investigation of their tissue origins. Biochem J 1997; 321 ( Pt 1):117-23. [PMID: 9003409 PMCID: PMC1218044 DOI: 10.1042/bj3210117] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Bovine respiratory secretions were separated into gel and sol phases to allow the identification of the gel-forming mucins. Mucins were subsequently isolated from the surface epithelium and submucosal tissue to investigate the tissue origins of the species in the secretions. Density-gradient centrifugation revealed 'high-density' and 'low-density' mucins in the gel phase of the secretions. The 'high-density' mucins were large, composed of subunits joined by disulphide bonds and contained two highly glycosylated domains of apparently different lengths, whereas the 'low-density' mucins were smaller and monomeric. The sol also contained both 'high-density' and 'low-density' species. A 'high-density' mucin similar to that in the gel was isolated from the surface epithelium, suggesting that the goblet cells produce large, gel-forming mucins. A second 'high-density' species was released from the submucosal tissue after reduction/alkylation, indicating that large mucins from the submucosal glands may also be a component of the mucus gel. In addition, two small, 'low-density' mucins were obtained from the submucosal tissue. One species was associated with the gel phase but was also present in the sol, whereas the other was present only in the sol. Bovine respiratory-tract secretions thus comprise a complex mixture of large gel-forming mucins originating from the goblet cells and submucosal glands, and smaller 'soluble' species from the submucosal glands which may interact with the gel.
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Affiliation(s)
- H W Hovenberg
- Department of Cell and Molecular Biology, Lund University, Sweden
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Hovenberg HW, Davies JR, Herrmann A, Lindén CJ, Carlstedt I. MUC5AC, but not MUC2, is a prominent mucin in respiratory secretions. Glycoconj J 1996; 13:839-47. [PMID: 8910011 DOI: 10.1007/bf00702348] [Citation(s) in RCA: 175] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Airway mucus was collected from healthy and chronic bronchitic subjects. The chronic bronchitic sputum was separated into gel and sol phase by centrifugation and mucins were isolated using isopycnic density-gradient centrifugation in CsCl. The presence of the MUC5AC and MUC2 mucins was investigated with antisera raised against synthetic peptides with sequences from the respective apoproteins. The gel and sol phase of chronic bronchitic sputum as well as healthy respiratory secretions were shown to contain MUC5AC whereas the MUC2 mucin could not be detected. Rate-zonal centrifugation showed that the MUC5AC mucin was large, polydisperse in size and that reduction yielded subunits. Ion-exchange HPLC revealed the presence of two subunit populations in all secretions, the MUC5AC subunits always being the more acidic. MUC5AC is thus the first large, subunit-based, gel-forming respiratory mucin identified and this glycoprotein is biochemically distinct from at least one other population of large, gel-forming mucins also composed of subunits but lacking a genetic identity.
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Affiliation(s)
- H W Hovenberg
- Department of Cell and Molecular Biology, Lund University, Sweden
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Hovenberg HW, Davies JR, Carlstedt I. Different mucins are produced by the surface epithelium and the submucosa in human trachea: identification of MUC5AC as a major mucin from the goblet cells. Biochem J 1996; 318 ( Pt 1):319-24. [PMID: 8761488 PMCID: PMC1217624 DOI: 10.1042/bj3180319] [Citation(s) in RCA: 228] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Mucins were extracted from the epithelial surface and the submucosal tissue of human trachea in order to enrich glycoproteins from the goblet cells and the submucosal glands respectively. The macromolecules were purified using density-gradient centrifugation, and the presence of the MUC5AC mucin was investigated using an antiserum raised against a synthetic peptide based on the sequence of the MUC5AC apoprotein. Mucins from the surface epithelium showed a higher reactivity with the antiserum relative to carbohydrate than those from the submucosa, and ion-exchange HPLC of reduced subunits revealed the presence of two distinct mucin populations in the samples. The predominant species from the surface epithelium was more acidic than the major population from the submucosa and showed a strong reactivity with the anti-MUC5AC anti-serum. In contrast, the major portion of the submucosal mucins were less acidic and showed no MUC5AC reactivity, although a more acidic population did react with the antibody. Rate-zonal centrifugation showed that the MUC5AC mucin from the surface epithelium is smaller than the major submucosal mucin, and that both are composed of subunits. Immunolocalization confirmed that the MUC5AC mucin from human trachea originates from the goblet cells and that this glycoprotein is not a major product of the submucosal glands.
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Affiliation(s)
- H W Hovenberg
- Department of Cell and Molecular Biology, Lund University, Sweden
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Thornton DJ, Carlstedt I, Howard M, Devine PL, Price MR, Sheehan JK. Respiratory mucins: identification of core proteins and glycoforms. Biochem J 1996; 316 ( Pt 3):967-75. [PMID: 8670177 PMCID: PMC1217443 DOI: 10.1042/bj3160967] [Citation(s) in RCA: 134] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
At least eight mucin apoproteins are expressed by the tracheobronchial epithelium, but it is not known which, if any, of these are major constituents of the respiratory secretions responsible for the formation of the mucus gel. To address this we have isolated mucins from normal, asthmatic and chronic bronchitic secretions. The asthmatic mucin reduced subunits were fractionated into four populations (I-IV) by anion-exchange HPLC. Amino acid and monosaccharide compositional analysis, as well as M(r) and size measurements, indicate that two of these populations (I and II) are glycoforms of the same or related apoprotein(s) and that the other populations contain two different apoproteins. A panel of antibodies and antisera recognizing the variable number tandem repeat (VNTR) of specific mucin apoproteins did not, as predicted, react with the glycosylated molecules, but after deglycosylation the majority of these probes (with the exception of those to MUC2, which were negative) reacted at a low level with each of the subunit populations. In contrast, an antiserum against a non-VNTR sequence of MUC5AC identified one of the populations (III) as the MUC5AC mucin. The MUC5AC reduced subunit had an M(r) of 2.2 x 10(6) and an RG (radius of gyration) of 57 nm. The genetic identities of the major mucin (populations I and II) and a minor component (population IV) were not established. The MUC5AC mucin was also identified as a major component in the pooled normal secretions from 20 individuals, whereas in a chronic bronchitic sample it was only a minor constituent. Furthermore, in all these different respiratory secretions the MUC5AC mucin appears as a similar biochemical entity, as assessed by Mono Q chromatography and agarose electrophoresis, suggesting that it may have a well-defined pattern of glycosylation in the respiratory tract.
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Affiliation(s)
- D J Thornton
- Wellcome Trust Centre for Cell-Matrix Research, University of Manchester, School of Biological Sciences, U.K
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