Why Mouse Airway Submucosal Gland Serous Cells Do Not Secrete Fluid in Response to cAMP Stimulation

ABSTRACT Serpentine receptors such as smoothened and frizzled play important roles in cell fate determination during animal development. InDictyostelium discoideum, four serpentine cyclic AMP (cAMP) receptors (cARs) regulate expression of multiple classes of developmental genes. To understand their function, it is essential to know whether each cAR is coupled to a specific gene regulatory pathway or whether specificity results from the different developmental regulation of individual cARs. To distinguish between these possibilities, we measured gene induction in car1 car3 double mutant cell lines that express equal levels of either cAR1, cAR2, or cAR3 under a constitutive promoter. We found that all cARs efficiently mediate both aggregative gene induction by cAMP pulses and induction of postaggregative and prespore genes by persistent cAMP stimulation. Two exceptions to this functional promiscuity were observed. (i) Only cAR1 can mediate adenosine inhibition of cAMP-induced prespore gene expression, a phenomenon that was found earlier in wild-type cells. cAR1’s mediation of adenosine inhibition suggests that cAR1 normally mediates prespore gene induction. (ii) Only cAR2 allows entry into the prestalk pathway. Prestalk gene expression is induced by differentiation-inducing factor (DIF) but only after cells have been prestimulated with cAMP. We found that DIF-induced prestalk gene expression is 10 times higher in constitutive cAR2 expressors than in constitutive cAR1 or cAR3 expressors (which still have endogenous cAR2), suggesting that cAR2 mediates induction of DIF competence. Since in wild-type slugs cAR2 is expressed only in anterior cells, this could explain the so far puzzling observations that prestalk cells differentiate at the anterior region but that DIF levels are actually higher at the posterior region. After the initial induction of DIF competence, cAMP becomes a repressor of prestalk gene expression. This function can again be mediated by cAR1, cAR2, and cAR3.

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CFTR involvement in chloride, bicarbonate, and liquid secretion by airway submucosal glands

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1999.277.4.l694 ◽

1999 ◽

Vol 277 (4) ◽

pp. L694-L699 ◽

Cited By ~ 58

Author(s):

Stephen T. Ballard ◽

Laura Trout ◽

Zsuzsa Bebök ◽

E. J. Sorscher ◽

Angela Crews

Keyword(s):

Cystic Fibrosis ◽

Channel Blocker ◽

Polyclonal Antibodies ◽

Surface Epithelium ◽

Transmembrane Conductance Regulator ◽

Submucosal Gland ◽

Transmembrane Conductance ◽

Active Secretion ◽

Submucosal Glands ◽

Cystic Fibrosis Transmembrane

Previous studies demonstrated that ACh-induced liquid secretion by porcine bronchi is driven by active Cl− and H[Formula: see text] secretion. The present study was undertaken to determine whether this process was localized to submucosal glands and mediated by the cystic fibrosis transmembrane conductance regulator (CFTR). When excised, cannulated, and treated with ACh, porcine bronchi secreted 15.6 ± 0.6 μl ⋅ cm−2 ⋅ h−1. Removal of the surface epithelium did not significantly affect the rate of secretion, indicating that the source of the liquid was the submucosal glands. Pretreatment with diphenylamine-2-carboxylate, a relatively nonselective Cl−-channel blocker, significantly reduced liquid secretion by 86%, whereas pretreatment with DIDS, which inhibits a variety of Cl− channels but not CFTR, had no effect. When bronchi were pretreated with glibenclamide or 5-nitro-2-(3-phenylpropylamino)benzoic acid (both inhibitors of CFTR), the rate of ACh-induced liquid secretion was significantly reduced by 39 and 91%, respectively, compared with controls. Agents that blocked liquid secretion also caused disproportionate reductions in H[Formula: see text] secretion. Polyclonal antibodies to the CFTR bound preferentially to submucosal gland ducts and the surface epithelium, suggesting that this channel was localized to these sites. These data suggest that ACh-induced gland liquid secretion by porcine bronchi is driven by active secretion of both Cl− and H[Formula: see text] and is mediated by the CFTR.

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Mucus glycoconjugate secretion in cool and hypertonic solutions

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1997.272.6.l1121 ◽

1997 ◽

Vol 272 (6) ◽

pp. L1121-L1125 ◽

Cited By ~ 4

Author(s):

T. M. Dwyer ◽

J. M. Farley

Keyword(s):

Average Rate ◽

Transient Increase ◽

Productive Cough ◽

Submucosal Gland ◽

Basal Secretion ◽

Cold Air ◽

Dry Air ◽

Gland Cells ◽

Hypertonic Solutions ◽

Exercise Induced

For sensitive individuals, exercise-induced asthma is triggered by cold and dry air and is often accompanied by a productive cough. In this study, we determined whether cold solutions and/or solutions of increased tonicity directly caused an increase in glycoconjugate (GC) secretion. To test this, we used isolated swine tracheal submucosal gland cells (TSGCs) and measured the rate of GC secretion at 37 and 32 degrees C in isotonic solutions and in solutions made hypertonic by 30 mosM. TSGCs were isolated under conditions that minimized the rate of GC secretion and were perfused with medium 199 equilibrated with 5% CO2 to a pH of 7.4. A lectin-based assay was used to specifically detect GC present in each 2-min fraction of the perfusate. Basal secretion was 3.1-fold greater at 32 degrees C (n = 3) than at 37 degrees C (n = 4; P < 0.05). At 37 degrees C, increasing perfusate osmolarity by 30 mosM increased the average rate of secretion by 41 +/- 11% (n = 4; P < 0.05); return to isotonic perfusate caused a 4.5 +/- 1.8-fold transient increase in secretion (n = 4; P < 0.05) that was complete within 10 min. At 32 degrees C, changing tonicity of the perfusate had no significant effect but returning to isotonic perfusate caused a 2.3 +/- 0.7-fold transient increase in secretion (n = 3; P < 0.05). Thus key stimuli that trigger obstruction of airflow (cold and increased osmolarity) can also directly stimulate GC secretion in the airway. Such increased secretions may contribute to the productive cough observed in some individuals in response to cold air.

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Muscarinic receptor subtypes in feline tracheal submucosal gland secretion

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1992.262.2.l223 ◽

1992 ◽

Vol 262 (2) ◽

pp. L223-L228 ◽

Cited By ~ 7

Author(s):

H. Ishihara ◽

S. Shimura ◽

M. Satoh ◽

T. Masuda ◽

H. Nonaka ◽

...

Keyword(s):

Muscarinic Receptor ◽

Gland Secretion ◽

Receptor Subtype ◽

Receptor Subtypes ◽

Submucosal Gland ◽

Muscarinic Receptor Subtypes ◽

Binding Assays ◽

Submucosal Glands ◽

Electrolyte Secretion ◽

Quinuclidinyl Benzilate

To determine what muscarinic receptor subtype regulates [Ca2+]i mediating airway submucosal gland secretion, we examined the effects of atropine (Atr), pirenzepine (PZ), 11([2-(diethylamino)methyl-1-piperidinyl] acetyl)-5,11-dihydro-6H-pyrido (2,3-b)(1,4)-benzo-diazepin-6-one (AF-DX116) and 4-diphenylacetoxy-N-methyl-piperidine methiodide (4-DAMP) on methacholine (MCh)-evoked [Ca2+]i rise in acinar cells, and compared this with mucus glycoprotein (MGP) and electrolyte secretion evoked by MCh from submucosal glands isolated from feline trachea. [Ca2+]i was measured with the Ca(2+)-sensitive fluorescent dye, fura 2. We determined MGP secretion by measuring TCA-precipitable 3H-labeled glycoconjugates and electrolyte secretion by the change in the rate constant of 22Na-efflux from isolated glands. Half-maximal inhibitory concentrations (IC50) of PZ, AF-DX116, 4-DAMP, and Atr against MCh-evoked [Ca2+]i rise were 10(-7) M, 6 x 10(-6) M, 8 x 10(-9) M, and 6 x 10(-9) M, respectively. IC50 of PZ, AF-DX116, 4-DAMP, and Atr against MCh-evoked MGP secretion were 10(-6) M, 2 x 10(-5) M, 8 x 10(-9) M, and 6 x 10(-9) M, respectively. MCh (10(-5) M)-evoked 22Na efflux was significantly inhibited by 10(-7) M 4-DAMP and 10(-7) M Atr (P less than 0.01, each) but not by 10(-7) M PZ. Receptor binding assays with [3H]quinuclidinyl benzilate showed that the Ki values for PZ, AF-D x 116, 4-DAMP and Atr were 2.2 x 10(-8) M, 6.6 x 10(-7) M, 6.2 x 10(-10) M, and 2.9 x 10(-10) M, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

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Novel Stem/Progenitor Cell Population from Murine Tracheal Submucosal Gland Ducts with Multipotent Regenerative Potential

Stem Cells ◽

10.1002/stem.680 ◽

2011 ◽

Vol 29 (8) ◽

pp. 1283-1293 ◽

Cited By ~ 88

Author(s):

Ahmed E. Hegab ◽

Vi Luan Ha ◽

Jennifer L. Gilbert ◽

Kelvin Xi Zhang ◽

Stephen P. Malkoski ◽

...

Keyword(s):

Cell Population ◽

Progenitor Cell ◽

Submucosal Gland ◽

Progenitor Cell Population

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cAMP induces a rapid and reversible modification of the chemotactic receptor in Dictyostelium discoideum.

The Journal of Cell Biology ◽

10.1083/jcb.100.3.715 ◽

1985 ◽

Vol 100 (3) ◽

pp. 715-720 ◽

Cited By ~ 39

Author(s):

C Klein ◽

J Lubs-Haukeness ◽

S Simons

Keyword(s):

Dictyostelium Discoideum ◽

Concentration Dependence ◽

Time Course ◽

Camp Synthesis ◽

Sds Page ◽

Reversible Modification ◽

Camp Receptor ◽

Camp Stimulation ◽

Stimulation Of

Stimulation, within 1 min after cAMP stimulation, of aggregation-competent Dictyostelium discoideum amebae was found to cause a rapid (within 1 min) modification of the cell's surface cAMP receptor. The modified receptor migrated on SDS PAGE as a 47,000-mol-wt protein, as opposed to a 45,000-mol-wt protein labeled on unstimulated cells. The length of time this modified receptor could be detected depended upon the strength of the cAMP stimulus: 3-4 min after treatment with 10(-7) M cAMP, cells no longer possessed the 47,000-mol-wt form of the cAMP receptor. Instead, the 45,000-mol-wt form was present. Stimulation of cells with 10(-5) M cAMP, however, resulted in the persistent (over 15 min) expression of the modified receptor. The time course, concentration dependence, and specificity of stimulus for this cAMP-induced shift in the cAMP receptor were found to parallel the cAMP-stimulated phosphorylation of a 47,000-mol-wt protein. In addition, both phenomena were shown to occur in the absence of endogenous cAMP synthesis. The possibility that the cAMP receptor is phosphorylated in response to cAMP stimulation, and the role of this event in cell desensitization, are discussed.

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