scholarly journals Inverse regulation of secretion and inflammation in human airway gland serous cells by neuropeptides upregulated in allergy and asthma

2019 ◽  
Author(s):  
Derek B. McMahon ◽  
Michael A. Kohanski ◽  
Charles C.L. Tong ◽  
Peter Papagiannopoulos ◽  
Nithin D. Adappa ◽  
...  
Keyword(s):  
Inflammatory Responses ◽  
Fluid Secretion ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Inflammatory Stimuli ◽  
Mucus Rheology ◽  
Enhanced Secretion ◽  
Ion Substitution ◽  
Serous Cell ◽  
Conducting Airways

ABSTRACTAirway submucosal gland serous cells are sites of expression of the cystic fibrosis transmembrane conductance regulator (CFTR) and are important for fluid secretion in conducting airways from the nose down to small bronchi. We tested if serous cells from human nasal turbinate glands secrete bicarbonate (HCO3−), important for mucus polymerization, during stimulation with the cAMP-elevating agonist vasoactive intestinal peptide (VIP) and if this requires CFTR. Isoalted serous cells stimulated with VIP exhibited a ~20% cAMP-dependent decrease in cell volume and a ~0.15 unit decrease in intracellular pH (pHi), reflecting activation of Cl−and HCO3−secretion, respectively. Pharmacology, ion substitution, and studies using cells from CF patients suggest serous cell HCO3−secretion is mediated by conductive efflux directly through CFTR. Interestingly, we found that neuropeptide Y (NPY) reduced VIP-evoked secretion by blunting cAMP increases and reducing CFTR activation through Gi-coupled NPY1R. Culture of primary gland serous cells in a model that maintained a serous phenotype confirmed the activating and inhibiting effects of VIP and NPY, respectively, on fluid and HCO3−secretion. Moreover, VIP enhanced secretion of antimicrobial peptides and antimicrobial efficacy of gland secretions while NPY reduced antimicrobial secretions. In contrast, NPY enhanced the release of cytokines during inflammatory stimuli while VIP reduced cytokine release through a mechanism requiring CFTR conductance. As levels of VIP and NPY are up-regulated in disease like allergy, asthma, and chronic rhinosinusitis, the balance of these two peptides in the airway may control airway mucus rheology and inflammatory responses through gland serous cells.

scholarly journals Neuropeptide regulation of secretion and inflammation in human airway gland serous cells

2020 ◽  
Vol 55 (4) ◽  
pp. 1901386 ◽  
Author(s):  
Derek B. McMahon ◽  
Ryan M. Carey ◽  
Michael A. Kohanski ◽  
Charles C.L. Tong ◽  
Peter Papagiannopoulos ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Inflammatory Responses ◽  
Fluid Secretion ◽  
Antimicrobial Efficacy ◽  
Transmembrane Conductance Regulator ◽  
Cytokine Release ◽  
Transmembrane Conductance ◽  
Mucus Rheology ◽  
Peptide Secretion ◽  
Conducting Airways

Airway submucosal gland serous cells are sites of expression of the cystic fibrosis transmembrane conductance regulator (CFTR) and are important for fluid secretion in conducting airways. To elucidate how neuropeptides regulate serous cells, we tested if human nasal turbinate serous cells secrete bicarbonate (HCO3−), important for mucus polymerisation and antimicrobial peptide function, during stimulation with cAMP-elevating vasoactive intestinal peptide (VIP) and if this requires CFTR. Serous cells stimulated with VIP exhibited a ∼15–20% cAMP-dependent decrease in cell volume and a ∼0.15 unit decrease in intracellular pH (pHi), reflecting activation of Cl− and HCO3− secretion, respectively. HCO3− secretion was directly dependent on CFTR and was absent in cells from CF patients. In contrast, neuropeptide Y (NPY) reduced VIP-evoked cAMP increases, CFTR activation, and Cl−/HCO3− secretion. Culture of primary serous cells in a model that maintained a serous phenotype confirmed the activating and inhibiting effects of VIP and NPY, respectively, on fluid and HCO3− secretion. Moreover, VIP enhanced antimicrobial peptide secretion and antimicrobial efficacy of secretions while NPY reduced antimicrobial efficacy. In contrast, NPY enhanced cytokine release while VIP reduced cytokine release through a mechanism requiring CFTR. As levels of VIP and NPY are up-regulated in diseases like allergy, asthma, and chronic rhinosinusitis, the balance of these two peptides in the airway may control mucus rheology and inflammatory responses in serous cells. Furthermore, the loss of CFTR conductance in serous cells may contribute to CF pathophysiology by increasing serous cells inflammatory responses in addition to directly impairing Cl− and HCO3− secretion.

Ion transport across the jejunum in normal and cystic fibrosis mice

1995 ◽  
Vol 268 (3) ◽  
pp. G505-G513 ◽  
Author(s):  
B. R. Grubb
Keyword(s):  
Cystic Fibrosis ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Fluid Secretion ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Targeted Disruption ◽  
Cl Secretion ◽  
Ion Substitution ◽  
Cystic Fibrosis Transmembrane

Cystic fibrosis (CF) mice created by targeted disruption of the murine cystic fibrosis transmembrane conductance regulator gene lack adenosine 3',5'-cyclic monophosphate (cAMP)-mediated Cl- secretion and exhibit marked intestinal complications secondary to inadequate fluid secretion. The basal short-circuit current (Isc) in the normal murine jejuna [43.2 +/- 5.9 microA.cm-2, n = 10 (mean +/- SE)] exhibits marked spontaneous n = 10 (mean +/- SE)] exhibits marked spontaneous oscillations (amplitude = 47.9 microA.cm-2, n = 18), which were completely absent in the CF jejunum. Treatment of normal jejuna with the neuronal blocker tetrodotoxin completely eliminated the oscillations and decreased the Isc to levels not significantly different from the low basal Isc (5.4 +/- 2.8 microA.cm-2, n = 16) exhibited by CF tissue. Ion substitution studies revealed basal Isc in normal jejuna to be due primarily to Cl- secretion but these tissues appeared to be capable of HCO3- secretion as well. In contrast, CF jejuna spontaneously secreted neither Cl- nor HCO3-, which may indicate that CF jejuna have a defect in the ability to secrete both of these anions. Apical glucose elicited an electrogenic absorption of Na+ of identical magnitude in normal and CF jejuna. Without apical glucose, CF jejuna exhibited a very small Isc response to forskolin (delta 2.2 +/- 0.67 microA.cm-2, n = 10). However, in the presence of apical glucose, forskolin elicited an eightfold greater Isc response in the CF tissue (delta 17.2 +/- 4.8 microA.cm-2, n = 9).(ABSTRACT TRUNCATED AT 250 WORDS)

PAR-2-activated secretion by airway gland serous cells: role for CFTR and inhibition by Pseudomonas aeruginosa

2021 ◽  
Vol 320 (5) ◽  
pp. L845-L879
Author(s):  
Derek B. McMahon ◽  
Ryan M. Carey ◽  
Michael A. Kohanski ◽  
Nithin D. Adappa ◽  
James N. Palmer ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Fluid Secretion ◽  
Transmembrane Conductance Regulator ◽  
Contrast Imaging ◽  
Transmembrane Conductance ◽  
Intracellular Ca ◽  
Influx Pathways ◽  
Cf Transmembrane Conductance Regulator ◽  
Protease Activated Receptor 2 ◽  
Conducting Airways

Airway submucosal gland serous cells are important sites of fluid secretion in conducting airways. Serous cells also express the cystic fibrosis (CF) transmembrane conductance regulator (CFTR). Protease-activated receptor 2 (PAR-2) is a G protein-coupled receptor that activates secretion from intact airway glands. We tested if and how human nasal serous cells secrete fluid in response to PAR-2 stimulation using Ca2+ imaging and simultaneous differential interference contrast imaging to track isosmotic cell shrinking and swelling reflecting activation of solute efflux and influx pathways, respectively. During stimulation of PAR-2, serous cells exhibited dose-dependent increases in intracellular Ca2+. At stimulation levels >EC50 for Ca2+, serous cells simultaneously shrank ∼20% over ∼90 s due to KCl efflux reflecting Ca2+-activated Cl− channel (CaCC, likely TMEM16A)-dependent secretion. At lower levels of PAR-2 stimulation (<EC50 for Ca2+), shrinkage was not evident due to failure to activate CaCC. Low levels of cAMP-elevating VIP receptor (VIPR) stimulation, also insufficient to activate secretion alone, synergized with low-level PAR-2 stimulation to elicit fluid secretion dependent on both cAMP and Ca2+ to activate CFTR and K+ channels, respectively. Polarized cultures of primary serous cells also exhibited synergistic fluid secretion. Pre-exposure to Pseudomonas aeruginosa conditioned media inhibited PAR-2 activation by proteases but not peptide agonists in primary nasal serous cells, Calu-3 bronchial cells, and primary nasal ciliated cells. Disruption of synergistic CFTR-dependent PAR-2/VIPR secretion may contribute to reduced airway surface liquid in CF. Further disruption of the CFTR-independent component of PAR-2-activated secretion by P. aeruginosa may also be important to CF pathophysiology.

scholarly journals Infection by Toxoplasma gondii, a severe parasite in neonates and AIDS patients, causes impaired anion secretion in airway epithelia

2015 ◽  
Vol 112 (14) ◽  
pp. 4435-4440 ◽  
Author(s):  
Hong-Mei Guo ◽  
Jiang-Mei Gao ◽  
Yu-Li Luo ◽  
Yan-Zi Wen ◽  
Yi-Lin Zhang ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Toxoplasma Gondii ◽  
Infected Mouse ◽  
Inflammatory Responses ◽  
Short Circuit ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Airway Epithelia ◽  
Anion Secretion ◽  
Cystic Fibrosis Transmembrane

The airway epithelia initiate and modulate the inflammatory responses to various pathogens. The cystic fibrosis transmembrane conductance regulator-mediated Cl− secretion system plays a key role in mucociliary clearance of inhaled pathogens. We have explored the effects of Toxoplasma gondii, an opportunistic intracellular protozoan parasite, on Cl− secretion of the mouse tracheal epithelia. In this study, ATP-induced Cl− secretion indicated the presence of a biphasic short-circuit current (Isc) response, which was mediated by a Ca2+-activated Cl− channel (CaCC) and the cystic fibrosis transmembrane conductance regulator. However, the ATP-evoked Cl− secretion in T. gondii-infected mouse tracheal epithelia and the elevation of [Ca2+]i in T. gondii-infected human airway epithelial cells were suppressed. Quantitative reverse transcription–PCR revealed that the mRNA expression level of the P2Y2 receptor (P2Y2-R) increased significantly in T. gondii-infected mouse tracheal cells. This revealed the influence that pathological changes in P2Y2-R had on the downstream signal, suggesting that P2Y2-R was involved in the mechanism underlying T. gondii infection in airways. These results link T. gondii infection as well as other pathogen infections to Cl− secretion, via P2Y2-R, which may provide new insights for the treatment of pneumonia caused by pathogens including T. gondii.

scholarly journals Convective washout reduces the antidiarrheal efficacy of enterocyte surface–targeted antisecretory drugs

2013 ◽  
Vol 141 (2) ◽  
pp. 261-272 ◽  
Author(s):  
Byung-Ju Jin ◽  
Jay R. Thiagarajah ◽  
A.S. Verkman
Keyword(s):  
Three Dimensional ◽  
Fluid Secretion ◽  
Transmembrane Conductance Regulator ◽  
Inhibitor Concentration ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Transmembrane Conductance ◽  
Convection Diffusion ◽  
Cystic Fibrosis Transmembrane ◽  
Dissociation Constant Kd

Secretory diarrheas such as cholera are a major cause of morbidity and mortality in developing countries. We previously introduced the concept of antisecretory therapy for diarrhea using chloride channel inhibitors targeting the cystic fibrosis transmembrane conductance regulator channel pore on the extracellular surface of enterocytes. However, a concern with this strategy is that rapid fluid secretion could cause convective drug washout that would limit the efficacy of extracellularly targeted inhibitors. Here, we developed a convection–diffusion model of washout in an anatomically accurate three-dimensional model of human intestine comprising cylindrical crypts and villi secreting fluid into a central lumen. Input parameters included initial lumen flow and inhibitor concentration, inhibitor dissociation constant (Kd), crypt/villus secretion, and inhibitor diffusion. We modeled both membrane-impermeant and permeable inhibitors. The model predicted greatly reduced inhibitor efficacy for high crypt fluid secretion as occurs in cholera. We conclude that the antisecretory efficacy of an orally administered membrane-impermeant, surface-targeted inhibitor requires both (a) high inhibitor affinity (low nanomolar Kd) to obtain sufficiently high luminal inhibitor concentration (&gt;100-fold Kd), and (b) sustained high luminal inhibitor concentration or slow inhibitor dissociation compared with oral administration frequency. Efficacy of a surface-targeted permeable inhibitor delivered from the blood requires high inhibitor permeability and blood concentration (relative to Kd).

scholarly journals Expression of ENaC subunits, chloride channels, and aquaporins in ovine fetal lung: ontogeny of expression and effects of altered fetal cortisol concentrations

2009 ◽  
Vol 297 (2) ◽  
pp. R453-R461 ◽  
Author(s):  
Nathan M. Jesse ◽  
Jarret McCartney ◽  
Xiaodi Feng ◽  
Elaine M. Richards ◽  
Charles E. Wood ◽  
...  
Keyword(s):  
Ion Channels ◽  
Chloride Channels ◽  
Fetal Lung ◽  
Fluid Secretion ◽  
Late Gestation ◽  
Transmembrane Conductance Regulator ◽  
Ontogenetic Changes ◽  
Transmembrane Conductance ◽  
Fetal Sheep ◽  
Ovine Fetal

Transition of the epithelium of the fetal lung from fluid secretion to fluid reabsorption requires changes in the expression of ion channels. Corticosteroids regulate expression of several of these channels, including the epithelium sodium channel (ENaC) subunits and aquaporins (AQP). We investigated the ontogenetic changes in these ion channels in the ovine fetal lung during the last half of gestation, a time of increasing adrenal maturation. Expression of the mRNAs for the chloride channels, cystic fibrosis transmembrane conductance regulator (CFTR), and chloride channel 2 (CLCN2) decreased with age. Expression of mRNAs for AQP1, AQP5, and for subunits of ENaC (α, β, γ) increased with age. In the fetal sheep the expression of ENaCβ mRNA was dramatically higher than the expression of ENaCα or ENaCγ, but expression of ENaCβ protein decreased with maturation, although the ratio of the mature (112 kDa) to immature (102 kDa) ENaCβ protein increased with age, particularly in the membrane fraction. In contrast, ENaCα mRNA and protein both increase with maturation, and the mature form of ENaCα (68 kDa) predominates at all ages. A modest increase in fetal cortisol, within the range expected to occur naturally in late gestation but prior to active labor, increased ENaCα mRNA but not ENaCβ, ENaCγ, or AQP mRNAs. We conclude that in the ovine fetal lung, appearance of functional sodium channels is associated with induction of ENACα and ENaCγ, and that ENaCα expression may be induced by even small, preterm increases in fetal cortisol.

scholarly journals A Rapid Membrane Potential Assay to Monitor CFTR Function and Inhibition

2013 ◽  
Vol 18 (9) ◽  
pp. 1132-1137 ◽  
Author(s):  
Rangan Maitra ◽  
Perumal Sivashanmugam ◽  
Keith Warner
Keyword(s):  
Cystic Fibrosis ◽  
Membrane Potential ◽  
Genetic Disorder ◽  
Fluid Secretion ◽  
Secretory Diarrhea ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Important Regulator ◽  
Cftr Protein ◽  
Cystic Fibrosis Transmembrane

The cystic fibrosis transmembrane conductance regulator (CFTR) protein is an important regulator of ion transport and fluid secretion in humans. Mutations to CFTR cause cystic fibrosis, which is a common recessive genetic disorder in Caucasians. Involvement of CFTR has been noted in other important diseases, such as secretory diarrhea and polycystic kidney disease. The assays to monitor CFTR function that have been described to date either are complicated or require specialized instrumentation and training for execution. In this report, we describe a rapid FlexStation-based membrane potential assay to monitor CFTR function. In this assay, agonist-mediated activation of CFTR results in membrane depolarization that can be monitored using a fluorescent membrane potential probe. Availability of a simple mix-and-read assay to monitor the function of this important protein might accelerate the discovery of CFTR ligands to study a variety of conditions.

scholarly journals Herbal components of Japanese Kampo medicines exert laxative actions in colonic epithelium cells via activation of BK and CFTR channels

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Tomohiro Numata ◽  
Kaori Sato-Numata ◽  
Yasunobu Okada
Keyword(s):  
Fluid Secretion ◽  
Bk Channels ◽  
Bk Channel ◽  
Colonic Epithelium ◽  
Transmembrane Conductance Regulator ◽  
Transmembrane Conductance ◽  
Cell Current ◽  
Current Characteristics ◽  
Cell Sizing ◽  
Herbal Components

Abstract Japanese Kampo medicines Junchoto and Mashiningan are mixtures of numerous herbal plant extracts and empirically known to exert laxative actions by stimulating fluid secretion in the colonic epithelium. However, it is unknown which and how the herbal components of these crude Kampo drugs are effective to stimulate ion effluxes causing fluid secretion. Here, we selected four herbal components of Junchoto and Mashiningan, Mashinin (MSN), Kyonin (KYN), Tonin (TON), and Daio (DIO), which are putatively laxatives, and examined their effects on the ion channel activity of human colonic epithelial Caco-2 cells. Patch clamp analyses revealed that MSN activated whole-cell current characteristics of the cystic fibrosis transmembrane conductance regulator (CFTR) channel, whereas KYN, TON, and DIO activated the large-conductance and voltage-activated K+ (BK) channel. Furthermore, electronic cell sizing showed that MSN induced secretory volume decrease (SVD) sensitivity to a CFTR blocker, whereas TON, KYN, and DIO induced SVD sensitivity to a K+ channel blocker. In conclusion, MSN and TON, KYN, and DIO promote fluid secretion from colonic epithelial cells by activating CFTR and BK channels. Thus, Japanese Kampo medicines, Junchoto and Mashiningan, exert anti-constipation actions by inducing KCl efflux through the combined actions of CFTR- and BK-stimulating herbal components.

Sign in / Sign up

Export Citation Format

Share Document