Regulation of CFTR channels by bicarbonate-sensitive soluble adenylyl cyclase in human airway epithelial cells

2005 ◽  
Author(s):  
Chak Sum Lam
Keyword(s):  
Epithelial Cells ◽  
Adenylyl Cyclase ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Soluble Adenylyl Cyclase ◽  
Human Airway ◽  
Human Airway Epithelial Cells

Regulation of CFTR channels by HCO3−-sensitive soluble adenylyl cyclase in human airway epithelial cells

2005 ◽  
Vol 289 (5) ◽  
pp. C1145-C1151 ◽  
Author(s):  
Yan Wang ◽  
Chak Sum Lam ◽  
Fan Wu ◽  
Wen Wang ◽  
Yuanyuan Duan ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Adenylyl Cyclase ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Adenylyl Cyclases ◽  
Open Probability ◽  
Soluble Adenylyl Cyclase ◽  
Human Airway ◽  
Human Airway Epithelium ◽  
Polymerase Chain

CFTR channels conduct HCO3− in addition to Cl− in airway epithelial cells. A defective HCO3−-transporting function of CFTR may underlie the pathogenesis of cystic fibrosis. In the present study, we have investigated whether a HCO3−-sensitive soluble adenylyl cyclase (sAC) is functionally coupled with CFTR and thus forms an autoregulatory mechanism for HCO3− transport in human airway epithelial Calu-3 cells. A reverse transcriptase-polymerase chain reaction showed that transcripts of both full-length and truncated sACs are present in Calu-3 cells. Truncated sAC protein is the predominant, if not the only, isoform expressed in Calu-3 cells. HCO3− stimulated a modest increase in cAMP production, and the increase was sensitive to 2-hydroxyestradiol (2-HE), a sAC inhibitor, but not to SQ22,536, a blocker of conventional transmembrane adenylyl cyclases. These results suggest that sAC is functional in Calu-3 cells. Adding 25 mM HCO3− to the bath stimulated CFTR-mediated whole cell currents in the absence, but not in the presence, of 2-HE. In cell-attached membrane patches, 25 or 50 mM HCO3− in the bath markedly increased the product of channel number and open probability of CFTR, and this activation was attenuated by 2-HE. These findings demonstrate that sAC signaling pathway is involved in the regulation of CFTR function in human airway epithelium and thereby provides a link between the level of intracellular HCO3−/CO2 and the modulation of HCO3−-conductive CFTR function by cAMP/PKA.

ICAM-1-independent adhesion of neutrophils to phorbol ester-stimulated human airway epithelial cells

1999 ◽  
Vol 277 (3) ◽  
pp. L465-L471 ◽  
Author(s):  
Alessandro Celi ◽  
Silvana Cianchetti ◽  
Stefano Petruzzelli ◽  
Stefano Carnevali ◽  
Filomena Baliva ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Airway Epithelial Cells ◽  
Bronchial Epithelial Cells ◽  
Neutrophil Adhesion ◽  
Late Time ◽  
Airway Epithelial ◽  
Bronchial Epithelial ◽  
Human Airway ◽  
Stimulation Of ◽  
Human Airway Epithelial Cells

Intercellular adhesion molecule-1 (ICAM-1) is the only inducible adhesion receptor for neutrophils identified in bronchial epithelial cells. We stimulated human airway epithelial cells with various agonists to evaluate whether ICAM-1-independent adhesion mechanisms could be elicited. Phorbol 12-myristate 13-acetate (PMA) stimulation of cells of the alveolar cell line A549 caused a rapid, significant increase in neutrophil adhesion from 11 ± 3 to 49 ± 7% (SE). A significant increase from 17 ± 4 to 39 ± 6% was also observed for neutrophil adhesion to PMA-stimulated human bronchial epithelial cells in primary culture. Although ICAM-1 expression was upregulated by PMA at late time points, it was not affected at 10 min when neutrophil adhesion was already clearly enhanced. Antibodies to ICAM-1 had no effect on neutrophil adhesion. In contrast, antibodies to the leukocyte integrin β-chain CD18 totally inhibited the adhesion of neutrophils to PMA-stimulated epithelial cells. These results demonstrate that PMA stimulation of human airway epithelial cells causes an increase in neutrophil adhesion that is not dependent on ICAM-1 upregulation.

scholarly journals Somatic cell hemoglobin modulates nitrogen oxide metabolism in the human airway epithelium

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nadzeya Marozkina ◽  
Laura Smith ◽  
Yi Zhao ◽  
Joe Zein ◽  
James F. Chmiel ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Nitrogen Oxides ◽  
Airway Epithelium ◽  
Airflow Obstruction ◽  
Airway Epithelial Cells ◽  
Airway Epithelial ◽  
Human Airway ◽  
Human Airway Epithelium ◽  
Human Airway Epithelial Cells

AbstractEndothelial hemoglobin (Hb)α regulates endothelial nitric oxide synthase (eNOS) biochemistry. We hypothesized that Hb could also be expressed and biochemically active in the ciliated human airway epithelium. Primary human airway epithelial cells, cultured at air–liquid interface (ALI), were obtained by clinical airway brushings or from explanted lungs. Human airway Hb mRNA data were from publically available databases; or from RT-PCR. Hb proteins were identified by immunoprecipitation, immunoblot, immunohistochemistry, immunofluorescence and liquid chromatography- mass spectrometry. Viral vectors were used to alter Hbβ expression. Heme and nitrogen oxides were measured colorimetrically. Hb mRNA was expressed in human ciliated epithelial cells. Heme proteins (Hbα, β, and δ) were detected in ALI cultures by several methods. Higher levels of airway epithelial Hbβ gene expression were associated with lower FEV1 in asthma. Both Hbβ knockdown and overexpression affected cell morphology. Hbβ and eNOS were apically colocalized. Binding heme with CO decreased extracellular accumulation of nitrogen oxides. Human airway epithelial cells express Hb. Higher levels of Hbβ gene expression were associated with airflow obstruction. Hbβ and eNOS were colocalized in ciliated cells, and heme affected oxidation of the NOS product. Epithelial Hb expression may be relevant to human airways diseases.

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