Regulation of MUC5AC mucin secretion and airway surface liquid metabolism by IL-1β in human bronchial epithelia

Gray, Thomas E.; Coakley, Raymond D.; Hirsh, Andrew J.; Thornton, David J.; Kirkham, Sara; Koo, Ja-Seok; Burch, Lauranell H.; Boucher, Richard C.; Nettesheim, Paul

doi:10.1152/ajplung.00440.2002

Cited by 98 publications

(96 citation statements)

References 53 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Partial inhibition of MUC5AC was induced by supernatant from LPS-treated MDM in contrast to the consistent increase of MUC5AC generated by a mix of pro-inflammatory cytokines, as well as by TNF-a and IL-1b alone, at levels found in MDM supernatant. However, our findings are in agreement with reports showing that IL-1b [47][48][49] and TNF-a 47 induce MUC5AC mRNA expression in HBEC. Additionally, significant inhibition of MUC5AC was observed in HBEC treated with supernatant from control MDM, whereas lack of consistent MUC5AC changes were observed in HBEC challenged with cytokines mimicking supernatant from control MDM.…”

Section: Discussionsupporting

confidence: 93%

Macrophages are related to goblet cell hyperplasia and induce MUC5B but not MUC5AC in human bronchus epithelial cells

Silva

Berčík

2012

Laboratory Investigation

View full text Add to dashboard Cite

Airway goblet cell hyperplasia (GCH)-detectable by mucin staining-and abnormal macrophage infiltrate are pathological features present in many chronic respiratory disorders. However, it is unknown if both factors are associated. Using in-vivo and in-vitro models, we investigated whether macrophages are related with GCH and changes in mucin immunophenotypes. Lung sections from Sprague-Dawley rats treated for 48 h with one intra-tracheal dose of PBS or LPS (n ¼ 4-6 per group) were immunophenotyped for rat-goblet cells, immune, and proliferation markers. Human monocytederived macrophages (MDM) were pre-treated with or without LPS, immunophenotyped, and their supernatant, as well as cytokines at levels equivalent to supernatant were used to challenge primary culture of normal human bronchus epithelial cells (HBEC) in air-liquid interface, followed by MUC5B and MUC5AC mucin immunostaining. An association between increased bronchiolar goblet cells and terminal-bronchiolar proliferative epithelial cells confirmed the presence of GCH in our LPS rat model, which was related with augmented bronchiolar CD68 macrophage infiltration. The in-vitro experiments have shown that MUC5AC phenotype was inhibited when HBEC were challenged with supernatant from MDM pre-treated with or without LPS. In contrast, TNF-a and interleukin-1b at levels equivalent to supernatant from LPS-treated MDM increased MUC5AC. MUC5B was induced by LPS, supernatant from LPS-treated MDM, a mix of cytokines including TNF-a and TNF-a alone at levels present in supernatant from LPS-treated MDM. We demonstrated that macrophages are related with bronchiolar GCH, and that they induced MUC5B and inhibited MUC5AC in HBEC, suggesting a role for them in the pathogenesis of airway MUC5B-related GCH. KEYWORDS: airways; cytokines; LPS; lung inflammation; TNF-alphaMucus is a gel that covers the airway epithelium and is constituted by different glycoproteins called mucins, which are secreted by goblet cells from submucosal glands and the airway epithelium. 1 Mucus dissolves noxious gases and entraps foreign particles and pathogens, facilitating their clearance by mucociliary transport as a mechanism of innate defense. 2 However, in chronic inflammatory respiratory diseases, such as asthma, chronic obstructive pulmonary disease (COPD), and cystic fibrosis (CF), there is a pathological goblet cell hyperplasia (GCH) and mucus hypersecretion that can generate airway occlusion, associated with morbidity and death. 1 The main gel-forming mucins found in human airways are MUC5B and MUC5AC. 1 In healthy individuals, low levels of MUC5B and MUC5AC can be detected in mucus; although MUC5B is mainly present in the submucosal glands and MUC5AC is predominantly distributed in the airway epithelium. 3 In baseline conditions of chronic inflammatory respiratory disorders, MUC5B and/or MUC5AC are increased in different compartments of the respiratory tract. [3][4][5][6] For example, MUC5B and MUC5AC are augmented in small airway lumen and epithelium from patients with advanced CF; 4 GC...

show abstract

Section: Discussionsupporting

confidence: 93%

Macrophages are related to goblet cell hyperplasia and induce MUC5B but not MUC5AC in human bronchus epithelial cells

Silva

Berčík

2012

Laboratory Investigation

View full text Add to dashboard Cite

show abstract

“…MUC5B is primarily secreted by submucosal glands, but also by airway goblet cells (2,3), and is thought to play mostly a protective role. In contrast, MUC5AC, which is exclusively produced by goblet cells (4), has been thought to play more of a pathologic role because of greatly increased MUC5AC expression with disease states (5)(6)(7)(8).…”

mentioning

confidence: 99%

Overexpressing mouse model demonstrates the protective role of Muc5ac in the lungs

Ehré

Worthington

Liesman

et al. 2012

Proc. Natl. Acad. Sci. U.S.A.

172

178

View full text Add to dashboard Cite

MUC5AC, a major gel-forming mucin expressed in the lungs, is secreted at increased rates in response to infectious agents, implying that mucins exert a protective role against inhaled pathogens. However, epidemiological and pathological studies suggest that excessive mucin secretion causes airways obstruction and inflammation. To determine whether increased MUC5AC secretion alone produces airway obstruction and/or inflammation, we generated a mouse model overexpressing Muc5ac mRNA ∼20-fold in the lungs, using the rCCSP promoter. The Muc5ac cDNA was cloned from mouse lungs and tagged internally with GFP. Bronchoalveolar lavage fluid (BALF) analysis demonstrated an approximate 18-fold increase in Muc5ac protein, which formed high-molecular-weight polymers. Histopathological studies and cell counts revealed no airway mucus obstruction or inflammation in the lungs of Muc5ac-transgenic (Muc5ac-Tg) mice. Mucus clearance was preserved, implying that the excess Muc5ac secretion produced an “expanded” rather than more concentrated mucus layer, a prediction confirmed by electron microscopy. To test whether the larger mucus barrier conferred increased protection against pathogens, Muc5ac-Tg animals were challenged with PR8/H1N1 influenza viruses and showed significant decreases in infection and neutrophilic responses. Plaque assay experiments demonstrated that Muc5ac-Tg BALF and purified Muc5ac reduced infection, likely via binding to α2,3-linked sialic acids, consistent with influenza protection in vivo. In conclusion, the normal mucus transport and absence of a pulmonary phenotype in Muc5ac-Tg mice suggests that mucin hypersecretion alone is not sufficient to trigger luminal mucus plugging or airways inflammation/goblet cell hyperplasia. In contrast, increased Muc5ac secretion appears to exhibit a protective role against influenza infection.

show abstract

“…The magnitude and timing (within an hour) of this effect was similar to the known secretagogue ATP-g-S. Other cytokines such as IL1B (interleukin 1, b) increase MUC5AC production 48 and secretion. 49 However, the effect was delayed for hours or days, suggesting that a secondary pathway was utilized for mucus production.…”

Section: Discussionmentioning

confidence: 99%

IL13 activates autophagy to regulate secretion in airway epithelial cells

et al. 2016

View full text Add to dashboard Cite

Cytokine modulation of autophagy is increasingly recognized in disease pathogenesis, and current concepts suggest that type 1 cytokines activate autophagy, whereas type 2 cytokines are inhibitory. However, this paradigm derives primarily from studies of immune cells and is poorly characterized in tissue cells, including sentinel epithelial cells that regulate the immune response. In particular, the type 2 cytokine IL13 (interleukin 13) drives the formation of airway goblet cells that secrete excess mucus as a characteristic feature of airway disease, but whether this process is influenced by autophagy was undefined. Here we use a mouse model of airway disease in which IL33 (interleukin 33) stimulation leads to IL13-dependent formation of airway goblet cells as tracked by levels of mucin MUC5AC (mucin 5AC, oligomeric mucus/gel forming), and we show that these cells manifest a block in mucus secretion in autophagy gene Atg16l1-deficient mice compared to wild-type control mice. Similarly, primary-culture human tracheal epithelial cells treated with IL13 to stimulate mucus formation also exhibit a block in MUC5AC secretion in cells depleted of autophagy gene ATG5 (autophagy-related 5) or ATG14 (autophagyrelated 14) compared to nondepleted control cells. Our findings indicate that autophagy is essential for airway mucus secretion in a type 2, IL13-dependent immune disease process and thereby provide a novel therapeutic strategy for attenuating airway obstruction in hypersecretory inflammatory diseases such as asthma, chronic obstructive pulmonary disease, and cystic fibrosis lung disease. Taken together, these observations suggest that the regulation of autophagy by Th2 cytokines is cell-context dependent.

show abstract

Regulation of MUC5AC mucin secretion and airway surface liquid metabolism by IL-1β in human bronchial epithelia

Cited by 98 publications

References 53 publications

Macrophages are related to goblet cell hyperplasia and induce MUC5B but not MUC5AC in human bronchus epithelial cells

Macrophages are related to goblet cell hyperplasia and induce MUC5B but not MUC5AC in human bronchus epithelial cells

Overexpressing mouse model demonstrates the protective role of Muc5ac in the lungs

IL13 activates autophagy to regulate secretion in airway epithelial cells

Contact Info

Product

Resources

About