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Event: 962

Key Event Title

A descriptive phrase which defines a discrete biological change that can be measured. More help

Increase, Mucin production

Short name
The KE short name should be a reasonable abbreviation of the KE title and is used in labelling this object throughout the AOP-Wiki. More help
Increase, Mucin production
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Biological Context

Structured terms, selected from a drop-down menu, are used to identify the level of biological organization for each KE. More help
Level of Biological Organization

Cell term

The location/biological environment in which the event takes place.The biological context describes the location/biological environment in which the event takes place.  For molecular/cellular events this would include the cellular context (if known), organ context, and species/life stage/sex for which the event is relevant. For tissue/organ events cellular context is not applicable.  For individual/population events, the organ context is not applicable.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help
Cell term
goblet cell

Organ term

The location/biological environment in which the event takes place.The biological context describes the location/biological environment in which the event takes place.  For molecular/cellular events this would include the cellular context (if known), organ context, and species/life stage/sex for which the event is relevant. For tissue/organ events cellular context is not applicable.  For individual/population events, the organ context is not applicable.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help
Organ term

Key Event Components

The KE, as defined by a set structured ontology terms consisting of a biological process, object, and action with each term originating from one of 14 biological ontologies (Ives, et al., 2017; Biological process describes dynamics of the underlying biological system (e.g., receptor signalling).Biological process describes dynamics of the underlying biological system (e.g., receptor signaling).  The biological object is the subject of the perturbation (e.g., a specific biological receptor that is activated or inhibited). Action represents the direction of perturbation of this system (generally increased or decreased; e.g., ‘decreased’ in the case of a receptor that is inhibited to indicate a decrease in the signaling by that receptor).  Note that when editing Event Components, clicking an existing Event Component from the Suggestions menu will autopopulate these fields, along with their source ID and description.  To clear any fields before submitting the event component, use the 'Clear process,' 'Clear object,' or 'Clear action' buttons.  If a desired term does not exist, a new term request may be made via Term Requests.  Event components may not be edited; to edit an event component, remove the existing event component and create a new one using the terms that you wish to add.  Further information on Event Components and Biological Context may be viewed on the attached pdf. More help
Process Object Action
gene expression mucin-5AC increased
translation mucin-5AC increased

Key Event Overview

AOPs Including This Key Event

All of the AOPs that are linked to this KE will automatically be listed in this subsection. This table can be particularly useful for derivation of AOP networks including the KE.Clicking on the name of the AOP will bring you to the individual page for that AOP. More help
AOP Name Role of event in AOP Point of Contact Author Status OECD Status
Decreased lung function KeyEvent Cataia Ives (send email) Under development: Not open for comment. Do not cite Under Development

Taxonomic Applicability

Latin or common names of a species or broader taxonomic grouping (e.g., class, order, family) that help to define the biological applicability domain of the KE.In many cases, individual species identified in these structured fields will be those for which the strongest evidence used in constructing the AOP was available in relation to this KE. More help
Term Scientific Term Evidence Link
human Homo sapiens High NCBI
mouse Mus musculus High NCBI
rat Rattus norvegicus High NCBI

Life Stages

An indication of the the relevant life stage(s) for this KE. More help
Life stage Evidence
Adult High

Sex Applicability

An indication of the the relevant sex for this KE. More help
Term Evidence
Mixed High

Key Event Description

A description of the biological state being observed or measured, the biological compartment in which it is measured, and its general role in the biology should be provided. More help

Mucins are a family of highly glycosylated proteins produced by epithelial tissues and constitute major macromolecular components of mucus which protects epithelium from chemical and mechanical damage (Dhanisha et al., 2018). Mucin production in healthy airway provides an important role in trapping and removing bacterial and viral pathogens and particulates. Similarly, mucus layer in the intestinal epithelium provides first line of defense against physical and chemical hazards, notably ingested food and bacteria (Kim and Ho, 2010). In airways, major gel-forming secreted mucins MUC5AC and MUC5B are primarily involved in defensive function. MUC2 is the major intestinal mucin but is also expressed in the airway epithelium, and MUC19 is the major mucin in salivary glands (Lillehoj et al., 2013). Specialized mucin-producing goblet cells increase mucin production in respiratory tract in response to various irritants and stressors (Rogers, 2003). Many stressors specifically induce mucin mRNA and protein production through activation of the epidermal growth factor receptor (EGFR) pathway (Nadel, 2013). However, other signaling pathways, not necessarily requiring EGFR activation, via STAT6, FOXA2 and SPDEF have also been implicated in mucin overexpression (Turner and Jones, 2009).  

Evidence for Perturbation by Stressor 

Various stressors such as cigarette smoke (Shao et al., 2004, Takeyama et al., 2001), reactive oxygen species (Yu et al., 2011, Casalino-Matsuda et al., 2009), phorbol 12-myristate 13-acetate (PMA) (Hewson et al., 2004), 2,3,7,8-tetrachlorodibenzodioxin (TCDD) (Lee et al., 2011), ozone (Wagner et al., 2003), fine particulate matter (Val et al., 2012), allergens such as ovalbumin (Song et al., 2016), as well as bacteria and viruses (Dohrman et al., 1998, Hao et al., 2014, Zhu et al., 2009) increase mucin production in respiratory airways. Wide range of inflammatory cytokines such as interleukin (IL) 1B, IL4, IL6, IL9, IL13, TNF, induce mucin production in different tissues, including respiratory and intestinal epithelium (Linden et al., 2008). Injection of the urban particulate matter into the middle ear cavity of rats increased MUC5AC and MUC5B expression in the middle ear mucosa (Park et al., 2014). Bacterial lipopolysaccharide (LPS) induced mucin expression in human intrahepatic biliary epithelial cells (HIBECs), colon adenocarcinoma cell line HT29, etc (Liu et al., 2013, Smirnova et al., 2003). 

How It Is Measured or Detected

A description of the type(s) of measurements that can be employed to evaluate the KE and the relative level of scientific confidence in those measurements.These can range from citation of specific validated test guidelines, citation of specific methods published in the peer reviewed literature, or outlines of a general protocol or approach (e.g., a protein may be measured by ELISA). Do not provide detailed protocols. More help

In the literature, increased mucin production is frequently equated with increased MUC5AC mRNA and protein expression and less frequently with changes in MUC5B, MUC2 mRNA and protein levels. Due to high molecular weight and extensive glycosylated nature of mucins, conventional polyacrylamide gel-based protein analytic approaches can be challenging for mucin measurements (Kesimer and Sheehan, 2012). Strategies and methods for measuring airway mucins are thoroughly described in a review by Atanasova and Reznikov (Atanasova and Reznikov, 2019). Below we list the methods commonly used for mucin production detection and measurement. 

  • Alterations in mucin genes (MUC5AC, MUC5B) expression in cell and tissue lysates are commonly assessed by RT-PCR or RT-qPCR (Yu et al., 2011, Shao et al., 2004, Lee et al., 2011, Wagner et al., 2003, Hao et al., 2014, Zhu et al., 2009, Val et al., 2012). For absolute quantification of MUC5AC and MUC5B transcript copy numbers droplet digital PCR can be performed (Okuda et al., 2019). 

  • In situ hybridization is used in some studies for mucin (MUC5AC, MUC5B, MUC2) mRNA quantification (Takeyama et al., 2001, Dohrman et al., 1998, Okuda et al., 2019). 

  • For mucin mRNA detection and quantification RNase protection assay (RPA) is also used (Dohrman et al., 1998). 

  • Northern blot of mucin mRNAs can also be applied for mucin gene expression measurement (Chen et al., 2006, Zuhdi Alimam et al., 2000). 

  • In addition, assessment of mucin gene promoter activity by reporter gene expression (e.g. luciferase assay) allows assumptions on mucin expression levels (Chen et al., 2006). 

  • Changes in mucin protein levels can be detected by Western blot in cell and tissue lysates using suitable antibodies (Lee et al., 2011, Okuda et al., 2019, Ramsey et al., 2016). 

  • As a quick alternative to Western blot, dot-blot /slot-blot assay can be performed (Thornton et al., 1989). 

  • Secreted mucin protein levels can be detected and quantified by Enzyme-Linked Immunosorbent Assay (ELISA) (Yu et al., 2011, Shao et al., 2004, Wagner et al., 2003, Dohrman et al., 1998, Song et al., 2016). ELISA method description for detection and quantification of mucin molecules can be found in the article from Steiger and colleagues (Steiger et al., 1994). 

  • Analytical techniques such as immunocyto/histochemistry/immunofluorescence in cytological preparations or histological tissue sections with an appropriate antibody are also common methods of mucin protein level quantification (Zhu et al., 2009, Okuda et al., 2019). For immunofluorescent assays fluorescent dyes such as fluorescein isothiocyanate, Alexa488, Alexa555 are applied with subsequent visualization (e.g. confocal laser scanning or fluorescence microscopy) (Yu et al., 2011, Casalino-Matsuda et al., 2009, Val et al., 2012).  

  • Immunoassay of MUC5AC protein is also used as mucin protein detection method, as described in the study of Takeyama and colleagues (Takeyama et al., 2001). 

  • MUC5AC positive cell number determination through flow cytometry is another method for comparing and quantifying stressor-treated samples to control samples (Val et al., 2012).  

  • For in vivo studies and clinical samples, an experienced pathologist may judge the presence and severity of mucin production on histological tissue sections stained with hematoxylin/eosin and Alcian blue and/or periodic acid Schiff stains (Song et al., 2016, Atanasova and Reznikov, 2019, Okuda et al., 2019). 

  • Mass spectrometric approaches could be utilized for targeted identification of mucins and their quantification in cell and tissue samples (Kesimer and Sheehan, 2012). 

Domain of Applicability

A description of the scientific basis for the indicated domains of applicability and the WoE calls (if provided).  More help

Evidence in support of this KE derives from in vitro studies with human cell systems (Casalino-Matsuda et al., 2009, Dohrman et al., 1998, Hao et al., 2014, Hewson et al., 2004, Lee et al., 2011, Val et al., 2012, Zhu et al., 2009), while corroborating in vivo evidence comes from studies in rodents (mouse or rat) (Hao et al., 2014, Song et al., 2016, Takeyama et al., 2001, Wagner et al., 2003). 


List of the literature that was cited for this KE description. More help

ATANASOVA, K. R. & REZNIKOV, L. R. 2019. Strategies for measuring airway mucus and mucins. Respir Res, 20, 261. 

CASALINO-MATSUDA, S. M., MONZON, M. E., DAY, A. J. & FORTEZA, R. M. 2009. Hyaluronan fragments/CD44 mediate oxidative stress-induced MUC5B up-regulation in airway epithelium. Am J Respir Cell Mol Biol, 40, 277-85. 

CHEN, Y., NICKOLA, T. J., DIFRONZO, N. L., COLBERG-POLEY, A. M. & ROSE, M. C. 2006. Dexamethasone-mediated repression of MUC5AC gene expression in human lung epithelial cells. Am J Respir Cell Mol Biol, 34, 338-47. 

DHANISHA, S. S., GURUVAYOORAPPAN, C., DRISHYA, S. & ABEESH, P. 2018. Mucins: Structural diversity, biosynthesis, its role in pathogenesis and as possible therapeutic targets. Crit Rev Oncol Hematol, 122, 98-122. 

DOHRMAN, A., MIYATA, S., GALLUP, M., LI, J. D., CHAPELIN, C., COSTE, A., ESCUDIER, E., NADEL, J. & BASBAUM, C. 1998. Mucin gene (MUC 2 and MUC 5AC) upregulation by Gram-positive and Gram-negative bacteria. Biochim Biophys Acta, 1406, 251-9. 

HAO, Y., KUANG, Z., JING, J., MIAO, J., MEI, L. Y., LEE, R. J., KIM, S., CHOE, S., KRAUSE, D. C. & LAU, G. W. 2014. Mycoplasma pneumoniae modulates STAT3-STAT6/EGFR-FOXA2 signaling to induce overexpression of airway mucins. Infect Immun, 82, 5246-55. 

HEWSON, C. A., EDBROOKE, M. R. & JOHNSTON, S. L. 2004. PMA induces the MUC5AC respiratory mucin in human bronchial epithelial cells, via PKC, EGF/TGF-alpha, Ras/Raf, MEK, ERK and Sp1-dependent mechanisms. J Mol Biol, 344, 683-95. 

KESIMER, M. & SHEEHAN, J. K. 2012. Mass spectrometric analysis of mucin core proteins. Methods Mol Biol, 842, 67-79. 

KIM, Y. S. & HO, S. B. 2010. Intestinal goblet cells and mucins in health and disease: recent insights and progress. Curr Gastroenterol Rep, 12, 319-30. 

LEE, Y. C., OSLUND, K. L., THAI, P., VELICHKO, S., FUJISAWA, T., DUONG, T., DENISON, M. S. & WU, R. 2011. 2,3,7,8-Tetrachlorodibenzo-p-dioxin-induced MUC5AC expression: aryl hydrocarbon receptor-independent/EGFR/ERK/p38-dependent SP1-based transcription. Am J Respir Cell Mol Biol, 45, 270-6. 

LILLEHOJ, E. P., KATO, K., LU, W. & KIM, K. C. 2013. Cellular and molecular biology of airway mucins. Int Rev Cell Mol Biol, 303, 139-202. 

LINDEN, S. K., SUTTON, P., KARLSSON, N. G., KOROLIK, V. & MCGUCKIN, M. A. 2008. Mucins in the mucosal barrier to infection. Mucosal Immunol, 1, 183-97. 

LIU, Z., TIAN, F., FENG, X., HE, Y., JIANG, P., LI, J., GUO, F., ZHAO, X., CHANG, H. & WANG, S. 2013. LPS increases MUC5AC by TACE/TGF-α/EGFR pathway in human intrahepatic biliary epithelial cell. Biomed Res Int, 2013, 165715. 

OKUDA, K., CHEN, G., SUBRAMANI, D. B., WOLF, M., GILMORE, R. C., KATO, T., RADICIONI, G., KESIMER, M., CHUA, M., DANG, H., LIVRAGHI-BUTRICO, A., EHRE, C., DOERSCHUK, C. M., RANDELL, S. H., MATSUI, H., NAGASE, T., O'NEAL, W. K. & BOUCHER, R. C. 2019. Localization of Secretory Mucins MUC5AC and MUC5B in Normal/Healthy Human Airways. Am J Respir Crit Care Med, 199, 715-727. 

PARK, M. K., CHAE, S. W., KIM, H. B., CHO, J. G. & SONG, J. J. 2014. Middle ear inflammation of rat induced by urban particles. Int J Pediatr Otorhinolaryngol, 78, 2193-7. 

RAMSEY, K. A., RUSHTON, Z. L. & EHRE, C. 2016. Mucin Agarose Gel Electrophoresis: Western Blotting for High-molecular-weight Glycoproteins. J Vis Exp. 

SHAO, M. X., NAKANAGA, T. & NADEL, J. A. 2004. Cigarette smoke induces MUC5AC mucin overproduction via tumor necrosis factor-alpha-converting enzyme in human airway epithelial (NCI-H292) cells. Am J Physiol Lung Cell Mol Physiol, 287, L420-7. 

SMIRNOVA, M. G., GUO, L., BIRCHALL, J. P. & PEARSON, J. P. 2003. LPS up-regulates mucin and cytokine mRNA expression and stimulates mucin and cytokine secretion in goblet cells. Cell Immunol, 221, 42-9. 

SONG, L., TANG, H., LIU, D., SONG, J., WU, Y., QU, S. & LI, Y. 2016. The Chronic and Short-Term Effects of Gefinitib on Airway Remodeling and Inflammation in a Mouse Model of Asthma. Cell Physiol Biochem, 38, 194-206. 

STEIGER, D., FAHY, J., BOUSHEY, H., FINKBEINER, W. E. & BASBAUM, C. 1994. Use of mucin antibodies and cDNA probes to quantify hypersecretion in vivo in human airways. Am J Respir Cell Mol Biol, 10, 538-45. 

TAKEYAMA, K., JUNG, B., SHIM, J. J., BURGEL, P. R., DAO-PICK, T., UEKI, I. F., PROTIN, U., KROSCHEL, P. & NADEL, J. A. 2001. Activation of epidermal growth factor receptors is responsible for mucin synthesis induced by cigarette smoke. Am J Physiol Lung Cell Mol Physiol, 280, L165-72. 

THORNTON, D. J., HOLMES, D. F., SHEEHAN, J. K. & CARLSTEDT, I. 1989. Quantitation of mucus glycoproteins blotted onto nitrocellulose membranes. Anal Biochem, 182, 160-4. 

VAL, S., BELADE, E., GEORGE, I., BOCZKOWSKI, J. & BAEZA-SQUIBAN, A. 2012. Fine PM induce airway MUC5AC expression through the autocrine effect of amphiregulin. Arch Toxicol, 86, 1851-9. 

WAGNER, J. G., VAN DYKEN, S. J., WIERENGA, J. R., HOTCHKISS, J. A. & HARKEMA, J. R. 2003. Ozone exposure enhances endotoxin-induced mucous cell metaplasia in rat pulmonary airways. Toxicol Sci, 74, 437-46. 

YU, H., LI, Q., ZHOU, X., KOLOSOV, V. P. & PERELMAN, J. M. 2011. Role of hyaluronan and CD44 in reactive oxygen species-induced mucus hypersecretion. Mol Cell Biochem, 352, 65-75. 

ZHU, L., LEE, P. K., LEE, W. M., ZHAO, Y., YU, D. & CHEN, Y. 2009. Rhinovirus-induced major airway mucin production involves a novel TLR3-EGFR-dependent pathway. Am J Respir Cell Mol Biol, 40, 610-9. 

ZUHDI ALIMAM, M., PIAZZA, F. M., SELBY, D. M., LETWIN, N., HUANG, L. & ROSE, M. C. 2000. Muc-5/5ac mucin messenger RNA and protein expression is a marker of goblet cell metaplasia in murine airways. Am J Respir Cell Mol Biol, 22, 253-60.