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MUC1: The First Respiratory Mucin with an Anti-Inflammatory Function. J Clin Med 2017; 6:jcm6120110. [PMID: 29186029 PMCID: PMC5742799 DOI: 10.3390/jcm6120110] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/22/2017] [Accepted: 11/24/2017] [Indexed: 02/07/2023] Open
Abstract
MUC1 is a membrane-bound mucin expressed on the apical surfaces of most mucosal epithelial cells. In normal lung epithelia, MUC1 is a binding site for Pseudomonas aeruginosa, an opportunistic human pathogen of great clinical importance. It has now been established that MUC1 also serves an anti-inflammatory role in the airways that is initiated late in the course of a bacterial infection and is mediated through inhibition of Toll-like receptor (TLR) signaling. MUC1 expression was initially shown to interfere with TLR5 signaling in response to P. aeruginosa flagellin, but has since been extended to other TLRs. These new findings point to an immunomodulatory role for MUC1 during P. aeruginosa lung infection, particularly during the resolution phase of inflammation. This review briefly summarizes the recent characterization of MUC1’s anti-inflammatory properties in both the respiratory tract and extrapulmonary tissues.
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Kim KC. Role of epithelial mucins during airway infection. Pulm Pharmacol Ther 2011; 25:415-9. [PMID: 22198062 DOI: 10.1016/j.pupt.2011.12.003] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Revised: 11/30/2011] [Accepted: 12/09/2011] [Indexed: 11/26/2022]
Abstract
Airway surface fluid contains two layers of mucins consisting mainly of 5 different mucin gene products. While the outer layer contains two gel-forming mucins (MUC5AC and MUC5B) that are tightly associated with various biologically active, defensive molecules, the inner layer contains three membrane-tethered mucins (MUC1, MUC4 and MUC16) shed from the apical cell surface. During airway infection, all of these mucins serve as a major protective barrier against pathogens. MUC1 mucin produced by virtually all the surface columnar epithelial cells in the respiratory tract as well as Type II pneumocytes in the alveoli plays an additional, perhaps more critical role during respiratory infection by controlling the resolution of inflammation that is essential to prevent the development of inflammatory lung disease.
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Affiliation(s)
- Kwang Chul Kim
- Lung Mucus Research Program, Center for Inflammation, Translational and Clinical Lung Research and Department of Physiology, Temple University School of Medicine, 3420 N. Broad Street, MRB-410, Philadelphia, PA 19140, USA.
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Finkbeiner WE, Zlock LT, Morikawa M, Lao AY, Dasari V, Widdicombe JH. Cystic fibrosis and the relationship between mucin and chloride secretion by cultures of human airway gland mucous cells. Am J Physiol Lung Cell Mol Physiol 2011; 301:L402-14. [PMID: 21724859 DOI: 10.1152/ajplung.00210.2010] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We investigated how cystic fibrosis (CF) alters the relationship between Cl(-) and mucin secretion in cultures of non-CF and CF human tracheobronchial gland mucous (HTGM and CFTGM, respectively) cells. Biochemical studies showed that HTMG cells secreted typical airway mucins, and immunohistochemical studies showed that these cells expressed MUC1, MUC4, MUC5B, MUC8, MUC13, MUC16, and MUC20. Effects of cumulative doses of methacholine (MCh), phenylephrine (Phe), isoproterenol (Iso), and ATP on mucin and Cl(-) secretion were studied on HTGM and CFTGM cultures. Baseline mucin secretion was not significantly altered in CFTGM cells, and the increases in mucin secretion induced by mediators were unaltered (Iso, Phe) or slightly decreased (MCh, ATP). Across mediators, there was no correlation between the maximal increases in Cl(-) secretion and mucin secretion. In HTGM cells, the Cl(-) channel blocker, diphenylamine-2-carboxylic acid, greatly inhibited Cl(-) secretion but did not alter mucin release. In HTGM cells, mediators (10(-5) M) increased mucin secretion in the rank order ATP > Phe = Iso > MCh. They increased Cl(-) secretion in the sequence ATP > MCh ≈ Iso > Phe. The responses in Cl(-) secretion to MCh, ATP, and Phe were unaltered by CF, but the response to Iso was greatly reduced. We conclude that mucin secretion by cultures of human tracheobronchial gland cells is independent of Cl(-) secretion, at baseline, and is unaltered in CF; that the ratio of Cl(-) secretion to mucus secretion varies markedly depending on mediator; and that secretions induced by stimulation of β-adrenergic receptors will be abnormally concentrated in CF.
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Affiliation(s)
- Walter E Finkbeiner
- Department of Pathology, University of California, San Francisco, 94110, USA.
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Kato K, Lillehoj EP, Kai H, Kim KC. MUC1 expression by human airway epithelial cells mediates Pseudomonas aeruginosa adhesion. Front Biosci (Elite Ed) 2010; 2:68-77. [PMID: 20036855 DOI: 10.2741/e67] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Human MUC1 (Muc1 in animals) is an extensively O-glycosylated membrane-tethered mucin expressed on the surface of epithelial cells and some cells of the hematopoietic system. Recently, we showed that the hamster Muc1 on Chinese hamster ovary (CHO) cells served as a binding site for Pseudomonas aeruginosa (PA) through interaction between bacterial flagellin and the Muc1 ectodomain. Because CHO cells are known to produce an atypical pattern of protein glycosylation, we determined whether or not PA interacted with MUC1 endogenously expressed on human airway epithelial cells. Knock down of MUC1 expression in bronchial (NuLi-1) or alveolar (A549) epithelial cells by RNA interference significantly reduced PA binding to the cells. Conversely, over-expression of MUC1 in HEK293 cells increased bacterial adherence. By confocal microscopy, PA and MUC1 were colocalized on the surface of NuLi-1 cells. Taken together, these results confirm our previous observations in CHO cells and suggest that MUC1 serves as a binding site for PA on the surface of airway epithelial cells, which may have important consequences in the pathogenesis of PA lung infections.
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Affiliation(s)
- Kosuke Kato
- Department of Physiology and Lung Center, Temple University School of Medicine, Philadelphia, PA 19140, USA
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Kim KC, Lillehoj EP. MUC1 mucin: a peacemaker in the lung. Am J Respir Cell Mol Biol 2008; 39:644-7. [PMID: 18617677 DOI: 10.1165/rcmb.2008-0169tr] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
MUC1 is a membrane-tethered mucin expressed on the surface of epithelial cells lining mucosal surfaces. Recent studies have begun to elucidate the physiologic function of MUC1 in the airways, pointing to an antiinflammatory role that is initiated late in the course of bacterial infection and is mediated through inhibition of TLR signaling. These new findings have great potential for clinical applications in controlling excessive and prolonged lung inflammation. This review briefly summarizes the protein structural features of MUC1 relevant to its function, the discovery of its antiinflammatory properties, and potential directions for future avenues of study.
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Affiliation(s)
- K Chul Kim
- Immunology and Asthma Program, Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108-5127, USA.
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Williams TI, Saggese DA, Muddiman DC. Studying O-Linked Protein Glycosylations in Human Plasma. J Proteome Res 2008; 7:2562-8. [DOI: 10.1021/pr800066e] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- Taufika Islam Williams
- W. M. Keck FT-ICR Mass Spectrometry Laboratory, Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695
| | - Diana A. Saggese
- W. M. Keck FT-ICR Mass Spectrometry Laboratory, Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695
| | - David C. Muddiman
- W. M. Keck FT-ICR Mass Spectrometry Laboratory, Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695
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Koga T, Kuwahara I, Lillehoj EP, Lu W, Miyata T, Isohama Y, Kim KC. TNF-alpha induces MUC1 gene transcription in lung epithelial cells: its signaling pathway and biological implication. Am J Physiol Lung Cell Mol Physiol 2007; 293:L693-701. [PMID: 17575006 DOI: 10.1152/ajplung.00491.2006] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The current study was conducted to elucidate the mechanism through which TNF-alpha stimulates expression of MUC1, a membrane-tethered mucin. A549 human lung alveolar cells treated with TNF-alpha exhibited significantly higher MUC1 protein levels in detergent lysates compared with cells treated with vehicle alone. Increased MUC1 protein levels were correlated with significantly higher levels of MUC1 mRNA in TNF-alpha-treated cells compared with controls. However, TNF-alpha did not alter MUC1 transcript stability, implying increased de novo transcription induced by the cytokine. TNF-alpha increased MUC1 gene promoter activity in A549 cells transfected with a promoter-luciferase reporter plasmid. Both U0126, an inhibitor of MEK1/2, and dominant negative ERK1 prevented TNF-alpha-induced MUC1 promoter activation, and anti-TNFR1 antibody blocked TNF-alpha-stimulated ERK1/2 activation. MUC1 promoter activation by TNF-alpha also was blocked by mithramycin A, an inhibitor of Sp1, as well as either deletion or mutation of a putative Sp1 binding site in the MUC1 promoter located between nucleotides -99 and -90. TNF-alpha-stimulated binding of Sp1 to the MUC1 promoter in intact cells was demonstrated by chromatin immunoprecipitation assay. We conclude that TNF-alpha induces MUC1 gene transcription through a TNFR1 --> MEK1/2 --> ERK1 --> Sp1 pathway.
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MESH Headings
- Animals
- Antigens, Neoplasm/genetics
- Antigens, Neoplasm/metabolism
- Binding Sites
- Cell Line, Tumor
- Cell Survival/drug effects
- Dose-Response Relationship, Drug
- Epithelial Cells/drug effects
- Epithelial Cells/metabolism
- Gene Expression Regulation, Neoplastic/drug effects
- Humans
- Lung/cytology
- Lung/drug effects
- Lung/metabolism
- Mice
- Mitogen-Activated Protein Kinase 3/metabolism
- Mucin-1
- Mucins/genetics
- Mucins/metabolism
- Promoter Regions, Genetic/genetics
- Protein Binding/drug effects
- RNA Stability/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Tumor Necrosis Factor, Type I/metabolism
- Signal Transduction/drug effects
- Sp1 Transcription Factor/metabolism
- Time Factors
- Transcription, Genetic/drug effects
- Tumor Necrosis Factor-alpha/pharmacology
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Affiliation(s)
- Takeshi Koga
- Lovelace Respiratory Research Institute, Albuquerque, New Mexico 87108, USA
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Kuwahara I, Lillehoj EP, Hisatsune A, Lu W, Isohama Y, Miyata T, Kim KC. Neutrophil elastase stimulates MUC1 gene expression through increased Sp1 binding to the MUC1 promoter. Am J Physiol Lung Cell Mol Physiol 2005; 289:L355-62. [PMID: 15849214 DOI: 10.1152/ajplung.00040.2005] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
We previously reported MUC1 was a cell surface receptor for Pseudomonas aeruginosa, and binding of bacteria to cells was significantly reduced by pretreatment with neutrophil elastase (NE) (Lillehoj EP, Hyun SW, Kim BT, Zhang XG, Lee DI, Rowland S, and Kim KC. Am J Physiol Lung Cell Mol Physiol 280: L181-L187, 2001). The current study was conducted to ascertain NE effects on MUC1 gene transcription, and MUC1 protein synthesis and degradation. A549 human lung carcinoma cells treated with NE exhibited significantly higher MUC1 protein levels in detergent lysates compared with cells treated with vehicle alone. Also, MUC1 protein shed into cell-conditioned medium was rapidly and completely degraded by NE. Actinomycin D blocked NE-stimulated increase in MUC1 protein expression, suggesting a mechanism of increased gene transcription that was confirmed by measurement of quantitatively greater MUC1 mRNA levels in NE-treated cells compared with controls. However, NE did not alter MUC1 mRNA stability, implying increased de novo transcription induced by the protease. NE increased promoter activity in A549 cells transfected with MUC1 gene promoter-luciferase reporter plasmid. This effect of NE was completely blocked by mithramycin A, an inhibitor of Sp1, as well as mutation of one of the putative Sp1 binding sites in MUC1 promoter located at -99/-90 relative to transcription initiation site. EMSA revealed NE enhanced binding of Sp1 to this 10-bp segment in a time-dependent manner. These results indicate the increase in MUC1 gene transcription by NE is mediated through increase in Sp1 binding to -99/-90 segment of MUC1 promoter.
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Affiliation(s)
- Ippei Kuwahara
- Dept. of Pharmaceutical Sciences, School of Pharmacy, Univ. of Maryland, 20 Penn St., Baltimore, MD 21201, USA
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Kim KC, Hisatsune A, Kim DJ, Miyata T. Pharmacology of airway goblet cell mucin release. J Pharmacol Sci 2003; 92:301-7. [PMID: 12939514 DOI: 10.1254/jphs.92.301] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Airway mucus hypersecretion is one of the major clinical manifestations of patients suffering from various pulmonary diseases. However, no drugs are yet available to control airway mucus hypersecretion. For the past 15 years, a plethora of information has amassed with regard to the pharmacology of airway goblet cell mucin secretion using various primary cell culture systems. The recent discovery of various MUC genes has also greatly stimulated research in this field. Nevertheless, the heterogeneity of the oligosaccharide structure of mucin molecules makes it extremely difficult to assess the significance of the information derived from the pharmacological studies. Therefore, it seems crucially important to understand the roles of individual mucins in conjunction with normal airway physiology and pathology, which should be the future research directions necessary for studying airway goblet cell mucin pharmacology.
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Affiliation(s)
- Kwang Chul Kim
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, 21201, USA.
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Lee IJ, Hyun SW, Nandi A, Kim KC. Transcriptional regulation of the hamster Muc1 gene: identification of a putative negative regulatory element. Am J Physiol Lung Cell Mol Physiol 2003; 284:L160-8. [PMID: 12388348 DOI: 10.1152/ajplung.00342.2000] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The mucin gene Muc1 is expressed in glandular epithelial cells and is involved in lubricative and protective functions. It is also overexpressed in many carcinomas including breast and lung cancer cells. To study the transcriptional regulation of Muc1, we cloned a 2.4-kb fragment containing the promoter region of the hamster Muc1 gene and analyzed it for its ability to mediate transcription. Transcriptional initiation was localized to 22 base pairs downstream of the TATA box. We performed functional analysis of the Muc1 promoter in hamster (HP-1 and Chinese hamster ovary) and human cells (MCF-7, A549, and BEAS-2B) using deletion/reporter constructs. A positive regulatory region between bases -555 and -252 and a putative negative regulatory element (P-NRE) between nucleotides -1,652 and -1,614 were found to be active in transfected cells. The P-NRE contains a yin yang 1 (YY1) transcription factor binding site, and electrophoretic mobility shift assays with HP-1 cell nuclear extract revealed the binding of YY1 to this site. Our data suggest that YY1 may play an inhibitory role in the transcription of the Muc1 gene.
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Affiliation(s)
- Insong James Lee
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, 20 N. Pine Street, Baltimore, MD 21201, USA
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Abstract
The airway surface liquid (ASL), often referred to as mucus, is a thin layer of fluid covering the luminal surface of the airway. The major function of mucus is to protect the lung through mucociliary clearance against foreign particles and chemicals entering the lung. The mucus is comprised of water, ions, and various kinds of macromolecules some of which possess the protective functions such as anti-microbial, anti-protease, and anti-oxidant activity. Mucus glycoproteins or mucins are mainly responsible for the viscoelastic property of mucus, which is crucial for the effective mucociliary clearance. There are at least eight mucin genes identified in the human airways, which will potentially generate various kinds of mucin molecules. At present, neither the exact structures of mucin proteins nor their regulation are understood although it seems likely that different types of mucins are involved in different functions and might also be associated with certain airway diseases. The fact that mucins are tightly associated with various macromolecules present in ASL seems to suggest that the defensive role of ASL is determined not only by these individual components but rather by a combination of these components. Collectively, mucins in ASL may be compared to aircraft carriers carrying various types of weapons in defense of airbome enemies.
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Affiliation(s)
- Erik R Lillehoj
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, USA
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Fujita T, Maruyama M, Araya J, Sassa K, Kawagishi Y, Hayashi R, Matsui S, Kashii T, Yamashita N, Sugiyama E, Kobayashi M. Hydrogen peroxide induces upregulation of Fas in human airway epithelial cells via the activation of PARP-p53 pathway. Am J Respir Cell Mol Biol 2002; 27:542-52. [PMID: 12397013 DOI: 10.1165/rcmb.4775] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Fas mediates apoptosis following binding with Fas ligand. Fas is expressed in human airway epithelial cells and has a critical role in the pathophysiology of various pulmonary disorders. Hydrogen peroxide (H(2)O(2)) is an important mediator of airway epithelial injury. In this context, we hypothesized that H(2)O(2) would increase the expression of cell surface Fas in human airway epithelial cells. To test this hypothesis, the modulation of Fas expression with H(2)O(2) was assessed in normal human bronchial epithelial cells and A549 cells. The majority of Fas was cytoplasmic in both cell types without any stimulation. Hydrogen peroxide significantly increased Fas in the plasma membrane fraction, while decreasing Fas in the cytoplasmic fraction. Incubation with an agonistic antibody for Fas induced apoptosis in H(2)O(2)-treated cells in proportion to the level of surface Fas expression on those cells. Inhibitors of poly(ADP-ribose) polymerase abrogated the H(2)O(2)-induced Fas translocation to the plasma membrane and p53 activation. Expression of dominant-negative p53 also inhibited the Fas translocation induced by H(2)O(2) in A549 cells. These results indicate that H(2)O(2) induces Fas upregulation by promoting cytoplasmic transport of Fas to the cell surface in human airway epithelial cells, and that the activation of the poly(ADP-ribose) polymerase-p53 pathway may be involved in this mechanism.
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Affiliation(s)
- Tadashi Fujita
- The First Department of Internal Medicine, Faculty of Medicine, Toyama Medical and Pharmaceutical University, Japan
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Meerzaman D, Shapiro PS, Kim KC. Involvement of the MAP kinase ERK2 in MUC1 mucin signaling. Am J Physiol Lung Cell Mol Physiol 2001; 281:L86-91. [PMID: 11404250 DOI: 10.1152/ajplung.2001.281.1.l86] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
MUC1 mucin is a receptor-like glycoprotein expressed abundantly in various cancer cell lines as well as in glandular secretory epithelial cells, including airway surface epithelial cells. The role of this cell surface mucin in the airway is not known. In an attempt to understand the signaling mechanism of MUC1 mucin, we established a stable cell line from COS-7 cells expressing a chimeric receptor consisting of the extracellular and transmembrane domains of CD8 and the cytoplasmic (CT) domain of MUC1 mucin (CD8/MUC1 cells). We previously observed that treatment of these cells with anti-CD8 antibody resulted in tyrosine phosphorylation of the CT domain of the chimera. Here we report that treatment of CD8/MUC1 cells with anti-CD8 resulted in activation of extracellular signal-regulated kinase (ERK) 2 as assessed by immunoblotting, kinase assay, and immunocytochemistry. The activation of ERK2 was completely blocked either by a dominant negative Ras mutant or in the presence of a mitogen-activated protein kinase kinase (MEK) inhibitor. We conclude that tyrosine phosphorylation of the CT domain of MUC1 mucin leads to activation of a mitogen-activated protein kinase pathway through the Ras-MEK-ERK2 pathway. Combined with the existing data by others, it is suggested that one of the roles of MUC1 mucin may be regulation of cell growth and differentiation via a common signaling pathway, namely the Grb2-Sos-Ras-MEK-ERK2 pathway.
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Affiliation(s)
- D Meerzaman
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, USA
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Lillehoj EP, Hyun SW, Kim BT, Zhang XG, Lee DI, Rowland S, Kim KC. Muc1 mucins on the cell surface are adhesion sites for Pseudomonas aeruginosa. Am J Physiol Lung Cell Mol Physiol 2001; 280:L181-7. [PMID: 11133508 DOI: 10.1152/ajplung.2001.280.1.l181] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Recently, we cloned and characterized a full-length cDNA of the hamster Muc1 gene, the expression of which appears to be associated with secretory cell differentiation (Park HR, Hyun SW, and Kim KC. Am J Respir Cell Mol Biol 15: 237-244, 1996). The role of Muc1 mucins in the airway, however, is unknown. In this study, we investigated whether cell surface mucins are adhesion sites for Pseudomonas aeruginosa. Chinese hamster ovary (CHO) cells not normally expressing Muc1 mucin were stably transfected with the hamster Muc1 cDNA, and binding to P. aeruginosa was examined. Our results showed that 1) stably transfected CHO cells expressed both Muc1 mRNA and Muc1 mucins based on Northern and Western blot analyses, 2) Muc1 mucins present on the cell surface were degraded by neutrophil elastase, and 3) expression of Muc1 mucins on the cell surface resulted in a significant increase in adhesion of P. aeruginosa that was completely abolished by either proteolytic cleavage with neutrophil elastase or deletion of the extracellular domain by mutation. We conclude that Muc1 mucins expressed on the surface of CHO cells serve as adhesion sites for P. aeruginosa, suggesting a possible role for these glycoproteins in the early stage of airway infection and providing a model system for studying epithelial cell responses to bacterial adhesion that leads to airway inflammation in general and cystic fibrosis in particular.
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Affiliation(s)
- E P Lillehoj
- Department of Pharmaceutical Sciences, University of Maryland School of Pharmacy, Baltimore, Maryland 21201, USA
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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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