VAMP8 Is The Vesicle SNARE For Mucin Secretion In Airway Goblet Cells

Author(s):  
Silvia M. Kreda ◽  
Lisa Jones ◽  
Lama Moussa ◽  
Leslie Fulcher ◽  
Yunxiang Zhu ◽  
...  
Keyword(s):  
2005 ◽  
Vol 288 (1) ◽  
pp. C46-C56 ◽  
Author(s):  
Camille Ehre ◽  
Andrea H. Rossi ◽  
Lubna H. Abdullah ◽  
Kathleen De Pestel ◽  
Sandra Hill ◽  
...  

Airway goblet cells secrete mucin onto mucosal surfaces under the regulation of an apical, phospholipase C/Gq-coupled P2Y2receptor. We tested whether cortical actin filaments negatively regulate exocytosis in goblet cells by forming a barrier between secretory granules and plasma membrane docking sites as postulated for other secretory cells. Immunostaining of human lung tissues and SPOC1 cells (an epithelial, mucin-secreting cell line) revealed an apical distribution of β- and γ-actin in ciliated and goblet cells. In goblet cells, actin appeared as a prominent subplasmalemmal sheet lying between granules and the apical membrane, and it disappeared from SPOC1 cells activated by purinergic agonist. Disruption of actin filaments with latrunculin A stimulated SPOC1 cell mucin secretion under basal and agonist-activated conditions, whereas stabilization with jasplakinolide or overexpression of β- or γ-actin conjugated to yellow fluorescent protein (YFP) inhibited secretion. Myristoylated alanine-rich C kinase substrate, a PKC-activated actin-plasma membrane tethering protein, was phosphorylated after agonist stimulation, suggesting a translocation to the cytosol. Scinderin (or adseverin), a Ca2+-activated actin filament severing and capping protein was cloned from human airway and SPOC1 cells, and synthetic peptides corresponding to its actin-binding domains inhibited mucin secretion. We conclude that actin filaments negatively regulate mucin secretion basally in airway goblet cells and are dynamically remodeled in agonist-stimulated cells to promote exocytosis.


2016 ◽  
Vol 68 (3) ◽  
pp. 641-649 ◽  
Author(s):  
Ivana Koledin ◽  
Renata Kovac ◽  
Vesna Rajkovic ◽  
Milica Matavulj

Acrylamide (AA) is an important industrial chemical worldwide. AA also forms naturally in many high-carbohydrate foods (bread, French fries, coffee, etc.) when they are heated. Since AA is ubiquitous in the human diet, and more than one-third of the calories we take in each day come from foods with detectable levels of acrylamide, the aim of this study was to determine the effect of subchronic AA treatment on colon goblet cell mucin secretion. Male Wistar rats were gavaged with AA for 5 days a week for 21 days. The animals were divided into three groups that were gavaged with different AA concentrations (0, 25, 50 mg/kg/day). Colon samples were processed for histochemical (PAS-AB, HID-AB) and immunohistochemical (anti-rat MUC2 antibody) staining to visualize mucins in the goblet cells. AA treatment showed an alteration in mucin production and secretion in that the amount of all investigated mucin types dropped. More prominent changes were detected in the upper crypt part where a decreased number of goblet cell was observed. AA treatment elicited a significant reduction in neutral mucins, while acidic mucins showed linearly decreasing trend with respect to AA doses. Also, a linear reduction of MUC2 mucins was noticed. Sulfomucins were absent in the colon lower crypt in all experimental groups, while in the upper crypt both sulfo- and sialomucins were significantly decreased. The results of our study point to changes in the synthesis, differentiation and distribution of mucins after AA treatment, which can have adverse effect on colorectal health.


2003 ◽  
Vol 285 (1) ◽  
pp. L149-L160 ◽  
Author(s):  
Lubna H. Abdullah ◽  
Jason T. Bundy ◽  
Camille Ehre ◽  
C. William Davis

SPOC1 cells, which are a mucin-secreting model of rat airway goblet cells, possess a luminal P2Y2 purinoceptor through which UTP, ATP, and ATPγS stimulate secretion with EC50 values of ∼3 μM. PMA elicits mucin secretion with high EC50 (75 nM) and saturation (300 nM) values. For the first time in airway mucin-secreting cells, the PKC isoforms expressed and activated by a secretagogue were determined using RT-PCR/restriction-enzyme mapping and Western blotting. Five isoforms were expressed: cPKCα, nPKCδ and -η, and aPKCζ and -ι/λ. PMA caused cPKCα and nPKCδ to translocate to the membrane fraction of SPOC1 cells; only nPKCδ so responded to ATPγS. Membrane-associated nPKCδ and mucin secretion increased in parallel with ATPγS concentration and yielded EC50 values of 2–3 μM and maximum values of 100 μM. Effects of PMA to increase membrane-associated cPKCα and nPKCδ saturated at 30 nM, whereas mucin secretion saturated at 300 nM, which suggests a significant PKC-independent effect of PMA on mucin secretion. A prime alternate phorbol ester-receptor candidate is the C1-domain protein MUNC13. RT-PCR revealed the expression of ubiquitous (ub)MUNC13-2 and its binding partner, DOC2-γ. Hence, P2Y2 agonists activate nPKCδ in SPOC1 cells. PMA activates cPKCα and nPKCδ at high affinity and stimulates a lower affinity PKC-independent pathway that leads to mucin secretion.


2007 ◽  
Vol 292 (1) ◽  
pp. L92-L98 ◽  
Author(s):  
Andrea H. Rossi ◽  
Wendy C. Salmon ◽  
Michael Chua ◽  
C. William Davis

Despite the general importance of Ca2+ signaling in signal transduction, and of goblet cell mucin hypersecretion in inflammatory pulmonary diseases, measurement of airway goblet cell intracellular Ca2+ (Ca[Formula: see text]) has not been reported. In this article, we describe the results of experiments measuring Ca[Formula: see text] in primary cultures of human bronchial goblet cells after stimulation with the purinergic agonist adenosine 5′- O-(3-thiotriphosphate) (ATPγS) and phorbol 12-myristate 13-acetate (PMA). Ca2+ signaling in human goblet cells after purinergic stimulation follows the classic paradigm of a Ca[Formula: see text] transient from a basal activity of 110 nM to a peak response of 260.1 ± 41.2 nM within 2 min, followed by a long superbasal plateau (155.3 ± 0.2 nM) between 10 and 15 min. The rise in Ca[Formula: see text] appears to result from a mobilization of intracellular stores, because the transient was nearly abolished by inhibition of PLC with the phosphatidylinositol-specific PLC inhibitor U-73122, and it was not affected significantly by removal of extracellular Ca2+. Loading goblet cells with BAPTA inhibited the ATPγS-induced Ca2+ transient by 86.0 ± 13.1%, relative to control. Finally, in contrast to the massive effects of high doses of PMA (300 nM) on mucin secretion from goblet cells, phorbol ester stimulated a small (27.1 ± 7% of the ATPγS control peak), brief rise in Ca[Formula: see text]. This diminutive signal likely denotes a local Ca2+ gradient, which may be associated with the mucin granule exocytotic process.


Tracheal mucin secretion has been measured from a segment of trachea, isolated in situ , in anaesthetized geese by a method that involves radioactive labelling of tracheal mucus glycoproteins (Gallagher et al. 1975). Goose tracheal mucus comes entirely from goblet cells, since the goose trachea does not contain submucosal mucous or serous glands, and this method has been used to investigate the nervous and pharmacological control of the mucin secretion from these epithelial goblet cells. The mucins secreted have been collected, fractionated, and chemically analysed. Intracellular mucin has been examined histochemically, and the results of electron microscopic observations of epithelial cells and nerves are presented. Acetylcholine increased tracheal mucin secretion, and this effect was completely blocked by atropine. Neither α- nor β-stimulant sympathomimetic amines affected tracheal mucin secretion. Stimulation of the peripheral cut ends of the descending oesophageal nerves increased tracheal mucin secretion and the majority of this response, approximately three-quarters, appeared to be cholinergic since this proportion was blocked by atropine. The mediator for the atropine-resistant part of the response is not known, but it appears not to be a β-adrenoreceptor stimulant since the response to nerve stimulation was unaffected by propranolol given at 34 μm intrasegmentally. Other possibilities are discussed. Atropine itself decreased the resting level of tracheal mucin secretion. The local anaesthetic, lignocaine, increased tracheal mucin secretion, while at the same time blocking the responses to acetylcholine and descending oesophageal nerve stimulation. The implications of this are discussed. The electrophoretic, gel filtration and ion-exchange properties of goose tracheal mucins showed that they represented high molecular mass, negatively charged glycoproteins which could be labelled biosynthetically with [ 35 S]sulphate, [ 3 H]- and [ 14 C]glucose. These mucins could be stained with Alcian blue or periodic acid Schiff reagent. The carbohydrate composition was unusual for an epithelial glycoprotein in that fucose was absent and mannose was present in small quantities. The monosaccharides present in larger quantity were galactose, N -acetylglucosamine, N -acetylgalactosamine and sialic acid. Histochemical analysis of tissue sections of gosling tracheas demonstrated that nearly all of the glycoprotein in epithelial goblet cells contained both sialic acid and sulphate residues. Sialated mucin was present also, but to a lesser extent, and many cells contained a mixture of sialated and sulphated mucins. The adult goose trachea had a high proportion of sialated glycoprotein. Electron microscopy showed a range of epithelial cell types and intra-epithelial nerves also. Many of the nerves had neurosecretory vesicles suggestive of motor function and some were near to goblet cells.


2015 ◽  
Vol 29 (S1) ◽  
Author(s):  
Robin Hodges ◽  
Dayu Li ◽  
Jeffrey Bair ◽  
Marie Shatos ◽  
Nan Chiang ◽  
...  

2020 ◽  
Vol 18 (3) ◽  
pp. 470-482 ◽  
Author(s):  
Menglu Yang ◽  
Marit Lippestad ◽  
Robin R. Hodges ◽  
Haakon K. Fjærvoll ◽  
Ketil A. Fjærvoll ◽  
...  

2005 ◽  
Vol 53 (10) ◽  
pp. 1305-1309 ◽  
Author(s):  
Juan Perez-Vilar ◽  
Carla M. Pedrosa Ribeiro ◽  
Wendy C. Salmon ◽  
Raean Mabolo ◽  
Richard C. Boucher

Live cell imaging methods were used to characterize goblet cells expressing a MUC5AC domain fused to enhanced green fluorescent protein that labels the granule lumen. Golgi complex and endosome/lysosome elements largely resided in the periphery of the granular mass. On the contrary, a tubular meshwork of endoplasmic reticulum (ER) was in close contact with the mucin granules. This meshwork could be identified in fixed native human bronchial goblet cells labeled with an anti-calreticulin antibody. The potential biological significance of this ER network for mucin secretion is discussed.


2019 ◽  
Vol 316 (1) ◽  
pp. L58-L70 ◽  
Author(s):  
Veronika E. Winkelmann ◽  
Kristin E. Thompson ◽  
Kathrin Neuland ◽  
Ana M. Jaramillo ◽  
Giorgio Fois ◽  
...  

Mucus clearance provides an essential innate defense mechanism to keep the airways and lungs free of particles and pathogens. Baseline and stimulated mucin secretion from secretory airway epithelial cells need to be tightly regulated to prevent mucus hypersecretion and mucus plugging of the airways. It is well established that extracellular ATP is a potent stimulus for regulated mucus secretion. Previous studies revealed that ATP acts via metabotropic P2Y2purinoreceptors on goblet cells. Extracellular ATP, however, is also a potent agonist for ionotropic P2X purinoreceptors. Expression of several P2X isoforms has been reported in airways, but cell type-specific expression and the function thereof remained elusive. With this study, we now provide evidence that P2X4is the predominant P2X isoform expressed in secretory airway epithelial cells. After IL-13 treatment of either human primary tracheal epithelial cells or mice, P2X4expression is upregulated in vitro and in vivo under conditions of chronic inflammation, mucous metaplasia, and hyperplasia. Upregulation of P2X4is strongest in MUC5AC-positive goblet cells. Moreover, activation of P2X4by extracellular ATP augments intracellular Ca2+signals and mucin secretion, whereas Ca2+signals and mucin secretion are dampened by inhibition of P2X4receptors. These data provide new insights into the purinergic regulation of mucin secretion and add to the emerging picture that P2X receptors modulate exocytosis of large secretory organelles and secretion of macromolecular vesicle cargo.


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