1057 - Bifidobacterium Dentium Increases Muc2 Synthesis and Activates Autophagy to Promote Mucin Release

Pendrin (SLC26A4), a Cl−/anion exchanger, is expressed at high levels in kidney, thyroid, and inner ear epithelia, where it has an essential role in bicarbonate secretion/chloride reabsorption, iodide accumulation, and endolymph ion balance, respectively. Pendrin is expressed at lower levels in other tissues, such as airways and esophageal epithelia, where it is transcriptionally regulated by the inflammatory cytokines interleukin (IL)-4 and IL-13 through a signal transducer and activator of transcription 6 (STAT6)-mediated pathway. In the airway epithelium, increased pendrin expression during inflammatory diseases leads to imbalances in airway surface liquid thickness and mucin release, while, in the esophageal epithelium, dysregulated pendrin expression is supposed to impact the intracellular pH regulation system. In this review, we discuss some of the recent findings on interleukin-mediated transcriptional regulation of pendrin and how this dysregulation impacts airway and esophagus epithelial homeostasis during inflammatory diseases.

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Comparative Evaluation of the Antimicrobial and Mucus Induction Properties of Selected Bacillus Strains against Enterotoxigenic Escherichia coli

Antibiotics ◽

10.3390/antibiotics9120849 ◽

2020 ◽

Vol 9 (12) ◽

pp. 849

Author(s):

Natalia Bravo Santano ◽

Erik Juncker Boll ◽

Lena Catrine Capern ◽

Tomasz Maciej Cieplak ◽

Enver Keleszade ◽

...

Keyword(s):

Escherichia Coli ◽

Functional Foods ◽

Animal Health ◽

Enterotoxigenic Escherichia Coli ◽

Mucus Production ◽

Ht29 Cells ◽

Bacillus Spp ◽

Mucin Release ◽

Strain Dependent ◽

Human Intestinal Cells

Probiotics have been shown to bind to host receptors, which are important for pathogen adhesion and induce the host’s production of defence factors. They can activate the goblet-cell-derived production of mucins, a major component of the mucus layer and a physical barrier participating in limiting the proximity of microorganisms to the epithelial layer. In the last decade, Bacillus spp. strains have gained interest in human and animal health due to their tolerance and stability under gastrointestinal tract conditions. Moreover, Bacillus spp. strains can also produce various antimicrobial peptides that can support their use as commercial probiotic supplements and functional foods. The present study aimed to evaluate and determine the ability of selected Bacillus spp. strains to inhibit the growth of enterotoxigenic Escherichia coli (ETEC) F4 and to reduce binding of ETEC F4 to HT29-16E (mucus-secreting and goblet-like) human intestinal cells. Moreover, mucus production in the HT29 cells in the presence of the Bacillus spp. strains was quantified by ELISA. Bacillus spp. strains (CHCC 15076, CHCC 15516, CHCC 15541, and CHCC 16872) significantly inhibited the growth of ETEC F4. Moreover, the ability of the probiotic Bacillus spp. strains to stimulate mucin release was highly strain dependent. The treatment with Bacillus subtilis CHCC 15541 resulted in a significant increase of both MUC2 and MUC3 in HT29-16E cells. Therefore, this strain could be an up-and-coming candidate for developing commercial probiotic supplements to prevent infections caused by ETEC F4 and, potentially, other pathogens.

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Ca2+ and protein kinase C activation of mucin granule exocytosis in permeabilized SPOC1 cells

AJP Cell Physiology ◽

10.1152/ajpcell.1998.275.1.c285 ◽

1998 ◽

Vol 275 (1) ◽

pp. C285-C292 ◽

Cited By ~ 93

Author(s):

C. E. Scott ◽

Lubna H. Abdullah ◽

C. William Davis

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Fold Increase ◽

Mucin Secretion ◽

Granule Exocytosis ◽

Kinase C ◽

Streptolysin O ◽

Intracellular Ca ◽

Mucin Release ◽

Protein Kinase C Activation

Mucin secretion by airway goblet cells is under the control of apical P2Y2, phospholipase C-coupled purinergic receptors. In SPOC1 cells, the mobilization of intracellular Ca2+ by ionomycin or the activation of protein kinase C (PKC) by phorbol 12-myristate 13-acetate (PMA) stimulates mucin secretion in a fully additive fashion [L. H. Abdullah, J. D. Conway, J. A. Cohn, and C. W. Davis. Am. J. Physiol. 273 ( Lung Cell. Mol. Physiol. 17): L201–L210, 1997]. This apparent independence between PKC and Ca2+ in the stimulation of mucin secretion was tested in streptolysin O-permeabilized SPOC1 cells. These cells were fully competent to secrete mucin when Ca2+ was elevated from 100 nM to 3.1 μM for 2 min following permeabilization; the Ca2+EC50 was 2.29 ± 0.07 μM. Permeabilized SPOC1 cells were exposed to PMA or 4α-phorbol at Ca2+ activities ranging from 10 nM to 10 μM. PMA, but not 4α-phorbol, increased mucin release at all Ca2+ activities tested: at 10 nM Ca2+ mucin release was 2.1-fold greater than control and at 4.7 μM Ca2+ mucin release was maximal (3.6-fold increase). PMA stimulated 27% more mucin release at 4.7 μM than at 10 nM Ca2+. Hence, SPOC1 cells possess Ca2+-insensitive, PKC-dependent, and Ca2+-dependent PKC-potentiated pathways for mucin granule exocytosis.

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