scholarly journals Chibby promotes ciliary vesicle formation and basal body docking during airway cell differentiation

2014 ◽  
Vol 207 (1) ◽  
pp. 123-137 ◽  
Author(s):  
Michael C. Burke ◽  
Feng-Qian Li ◽  
Benjamin Cyge ◽  
Takeshi Arashiro ◽  
Heather M. Brechbuhl ◽  
...  

Airway multiciliated epithelial cells play crucial roles in the mucosal defense system, but their differentiation process remains poorly understood. Mice lacking the basal body component Chibby (Cby) exhibit impaired mucociliary transport caused by defective ciliogenesis, resulting in chronic airway infection. In this paper, using primary cultures of mouse tracheal epithelial cells, we show that Cby facilitates basal body docking to the apical cell membrane through proper formation of ciliary vesicles at the distal appendage during the early stages of ciliogenesis. Cby is recruited to the distal appendages of centrioles via physical interaction with the distal appendage protein CEP164. Cby then associates with the membrane trafficking machinery component Rabin8, a guanine nucleotide exchange factor for the small guanosine triphosphatase Rab8, to promote recruitment of Rab8 and efficient assembly of ciliary vesicles. Thus, our study identifies Cby as a key regulator of ciliary vesicle formation and basal body docking during the differentiation of airway ciliated cells.

1997 ◽  
Vol 273 (1) ◽  
pp. G204-G216 ◽  
Author(s):  
L. al-Nakkash ◽  
C. U. Cotton

Secretion of salt and water by the epithelial cells that line pancreatic ducts depends on activation of apical membrane Cl- conductance. In the present study, we characterized two types of Cl- conductances present in the apical cell membrane of bovine pancreatic duct epithelial cells. Primary cultures of bovine main pancreatic duct epithelium and an immortalized cell line (BPD1) derived from primary cultures were used. Elevation of intracellular adenosine 3',5'-cyclic monophosphate (cAMP) or Ca2+ in intact monolayers of duct epithelium induced sustained anion secretion. Agonist-induced changes in plasma membrane Cl- permeability were accessed by 36 Cl- efflux, whole cell current recording, and measurements of transepithelial Cl- current across permeabilized epithelial monolayers. Elevation of intracellular cAMP elicited a sustained increase in Cl- permeability, whereas elevation of intracellular Ca2+ induced only a transient increase in Cl- permeability. Ca(2+)- but not cAMP-induced increases in Cl- permeability were abolished by preincubation of cells with the Ca2+ buffer 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, tetra(acetoxymethyl) ester (BAPTA-AM). N-phenylanthranilic acid (DPC; 1 mM) and glibenclamide (100 microM), but not 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS; 500 microM), inhibited the cAMP-induced increase in Cl- permeability. In contrast, DPC and DIDS, but not glibenclamide, inhibited the Ca(2+)-induced increase in Cl- permeability. We conclude from these experiments that bovine pancreatic duct epithelial cells express at least two types of Cl- channels, cAMP and Ca2+ activated, in the apical cell membrane. Because the Ca(2+)-activated increase in Cl- permeability is transient, the extent to which this pathway contributes to sustained anion secretion by the ductal epithelium remains to be determined.


2001 ◽  
Vol 280 (6) ◽  
pp. L1115-L1127 ◽  
Author(s):  
Tomoko Suzuki ◽  
Mutsuo Yamaya ◽  
Kiyohisa Sekizawa ◽  
Masayoshi Hosoda ◽  
Norihiro Yamada ◽  
...  

To examine the effects of bafilomycin A1, a blocker of vacuolar H+-ATPase, on rhinovirus (RV) infection in the airway epithelium, primary cultures of human tracheal epithelial cells were infected with RV14. Viral infection was confirmed by showing that viral RNA in the infected cells and the viral titers in the supernatants of infected cells increased with time. RV14 infection upregulated the production of cytokines and mRNA of intercellular adhesion molecule (ICAM)-1 in epithelial cells. Bafilomycin A1reduced the viral titers of RV14 and inhibited the production of cytokines and ICAM-1 before and after RV14 infection. Bafilomycin A1reduced susceptibility of epithelial cells to RV14 infection. RV14 increased activated nuclear factor-κB in the cells, and bafilomycin A1reduced the activated nuclear factor-κB. Bafilomycin A1decreased the number of acidic endosomes in the epithelial cells. These results suggest that bafilomycin A1may inhibit infection by RV14 by not only blocking RV RNA entry into the endosomes but also reducing ICAM-1 expression in the epithelial cells. Bafilomycin A1may therefore modulate airway inflammation after RV infection.


2000 ◽  
Vol 278 (3) ◽  
pp. L560-L571 ◽  
Author(s):  
Tomoko Suzuki ◽  
Mutsuo Yamaya ◽  
Kiyohisa Sekizawa ◽  
Norihiro Yamada ◽  
Katsutoshi Nakayama ◽  
...  

To examine the effects of glucocorticoid on rhinovirus (RV) infection, primary cultures of human tracheal epithelial cells were infected with either RV2 or RV14. Viral infection was confirmed by demonstrating that viral RNA in infected cells and viral titers of supernatants and lysates from infected cells increased with time. RV14 infection upregulated the expression of mRNA and protein of intercellular adhesion molecule-1 (ICAM-1), the major RV receptor, on epithelial cells, and it increased the production of interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α in supernatants. Dexamethasone reduced the viral titers of supernatants and cell lysates, viral RNA of infected cells, and susceptibility of RV14 infection in association with inhibition of cytokine production and ICAM-1 induction. In contrast to RV14 infection, dexamethasone did not alter RV2 infection, a minor group of RVs. These results suggest that dexamethasone may inhibit RV14 infection by reducing the surface expression of ICAM-1 in cultured human tracheal epithelial cells. Glucocorticoid may modulate airway inflammation via reducing the production of proinflammatory cytokines and ICAM-1 induced by rhinovirus infection.


1994 ◽  
Vol 266 (5) ◽  
pp. C1440-C1452 ◽  
Author(s):  
M. Haas ◽  
D. G. McBrayer

Chloride secretion in mammalian airway epithelia is stimulated by beta-adrenergic agonists via an adenosine 3',5'-cyclic monophosphate (cAMP)-dependent mechanism and by apical triphosphate nucleotides (ATP, UTP) via a cAMP-independent mechanism. Both types of secretagogues are known to stimulate apical Cl channels in airway cells; however, to maintain a stimulated rate of secretion, basolateral Cl influx via Na-K-Cl cotransport must be upregulated in parallel with apical Cl efflux. To examine the regulation of basolateral cotransport activity and its relationship to apical Cl efflux, we examined Cl transport in confluent primary cultures of dog tracheal epithelial cells treated with nystatin, an antibiotic that increases the permeability of plasma membranes to small monovalent ions, including Cl. By applying nystatin to the apical membrane of these cultures, apical Cl permeability could be increased to the point where transepithelial Cl transport is limited by transport across the basolateral membrane, which reflects primarily the activity of the cotransporter. In cultures of tracheal cells not treated with nystatin, transepithelial (basolateral-to-apical) 36Cl flux was increased two- to threefold by exposure to isoproterenol (5 microM, basolateral) or apical UTP (10 microM). Apical application of nystatin (400 units/ml) increased the basal level of transepithelial 36Cl flux approximately 1.5-fold and eliminated UTP stimulation of this flux, although an approximately twofold stimulation by isoproterenol persisted. Nystatin treatment also abolished UTP stimulation of saturable, basolateral [3H]bumetanide binding, a measure of functioning Na-K-Cl cotransporters in these cells; isoproterenol stimulation of binding was only mildly inhibited by nystatin treatment. Lowering intracellular Cl concentration ([Cl]i) by incubating cultures with apical media containing nystatin and reduced [Cl] (NO3 replacement) increased both basolateral-to-apical 36Cl flux and [3H]bumetanide binding in the absence of secretagogues or cell shrinkage. The results support our previous suggestion, based entirely on [3H]bumetanide binding [M. Haas, D. G. McBrayer, and J. R. Yankaskas. Am. J. Physiol. 264 (Cell. Physiol. 32): C189-C200, 1993], that UTP stimulation of basolateral Na-K-Cl cotransport in airway epithelial cells is entirely secondary to, and requires, an increase in apical Cl efflux, and further suggest that a decrease in [Cl]i may be a signal for cotransport activation in response to UTP. In addition, a cAMP-dependent cascade initiated by isoproterenol appears to directly stimulate the cotransporter.


2000 ◽  
Vol 278 (6) ◽  
pp. L1264-L1272 ◽  
Author(s):  
Barbara Ressler ◽  
Richard T. Lee ◽  
Scott H. Randell ◽  
Jeffrey M. Drazen ◽  
Roger D. Kamm

Smooth muscle constriction in asthma causes the airway to buckle into a rosette pattern, folding the epithelium into deep crevasses. The epithelial cells in these folds are pushed up against each other and thereby experience compressive stresses. To study the epithelial cell response to compressive stress, we subjected primary cultures of rat tracheal epithelial cells to constant elevated pressures on their apical surface (i.e., a transmembrane pressure) and examined changes in the expression of genes that are important for extracellular matrix production and maintenance of smooth muscle activation. Northern blot analysis of RNA extracted from cells subjected to transmembrane pressure showed induction of early growth response-1 (Egr-1), endothelin-1, and transforming growth factor-β1 in a pressure-dependent and time-dependent manner. Increases in Egr-1 protein were detected by immunohistochemistry. Our results demonstrate that airway epithelial cells respond rapidly to compressive stresses. Potential transduction mechanisms of transmembrane pressure were also investigated.


2001 ◽  
Vol 75 (23) ◽  
pp. 11834-11850 ◽  
Author(s):  
Max Ciarlet ◽  
Sue E. Crawford ◽  
Mary K. Estes

ABSTRACT Infection of epithelial cells by some animal rotaviruses, but not human or most animal rotaviruses, requires the presence ofN-acetylneuraminic (sialic) acid (SA) on the cell surface for efficient infectivity. To further understand how rotaviruses enter susceptible cells, six different polarized epithelial cell lines, grown on permeable filter membrane supports containing 0.4-μm pores, were infected apically or basolaterally with SA-independent or SA-dependent rotaviruses. SA-independent rotaviruses applied apically or basolaterally were capable of efficiently infecting both sides of the epithelium of all six polarized cell lines tested, while SA-dependent rotaviruses only infected efficiently through the apical surface of five of the polarized cell lines tested. Regardless of the route of virus entry, SA-dependent and SA-independent rotaviruses were released almost exclusively from the apical domain of the plasma membrane of polarized cells before monolayer disruption or cell lysis. The transepithelial electrical resistance (TER) of cells decreased at the same time, irrespective of whether infection with SA-independent rotaviruses occurred apically or basolaterally. The TER of cells infected apically with SA-dependent rotaviruses decreased earlier than that of cells infected basolaterally. Rotavirus infection decreased TER before the appearance of cytopathic effect and cell death and resulted in an increase in the paracellular permeability to [3H]inulin as a function of loss of TER. The presence of SA residues on either the apical or basolateral side was determined using a Texas Red-conjugated lectin, wheat germ agglutinin (WGA), which binds SA residues. WGA bound exclusively to SA residues on the apical surface of the cells, confirming the requirement for SA residues on the apical cell membrane for efficient infectivity of SA-dependent rotaviruses. These results indicate that the rotavirus SA-independent cellular receptor is present on both sides of the epithelium, but SA-dependent and SA-independent rotavirus strains infect polarized epithelial cells by different mechanisms, which may be relevant for pathogenesis and selection of vaccine strains. Finally, rotavirus-induced alterations of the epithelial barrier and paracellular permeability suggest that common mechanisms of pathogenesis may exist between viral and bacterial pathogens of the intestinal tract.


Blood ◽  
1988 ◽  
Vol 72 (1) ◽  
pp. 142-149 ◽  
Author(s):  
DR Ratcliffe ◽  
SL Nolin ◽  
EB Cramer

Abstract An in vitro model system was used to study the early neutrophil response to influenza-infected epithelia. In the absence of serum, neutrophil adherence to influenza-infected confluent monolayers of Madin-Darby canine kidney epithelial cells (MDCK) was approximately 590 times greater than neutrophil binding to control cultures. The leukocytes bound specifically to virus-infected cells. Neutrophil adherence to influenza-infected MDCK cells was monitored during the course of one replication cycle, and binding began at a time (4.5 hours) that coincided with viral protein insertion in the apical cell membrane. Ultrastructural examination at 4.5 hours showed that greater than 90% of the neutrophils adhered to the epithelial cell membrane in the absence of budding virus and, at 6.5 hours, 100% of the neutrophils adhered to the epithelium with emerging virions. The number of neutrophils bound to influenza-infected MDCK cells was not affected by the presence or absence of calcium or magnesium but did depend on the amount of viral inoculum and on the temperature of the culture. In direct contrast to hemadsorption of RBCs, neutrophil binding to influenza-infected MDCK cells was 100% greater at 37 degrees C than at 4 degrees C. The neutrophil surface molecules that bound influenza virus appeared to become functionally polarized because the adherence of neutrophils to budding influenza virus or to a virus-coated surface inhibited the neutrophils from binding additional influenza virus to their nonadherent surface.


2003 ◽  
Vol 285 (2) ◽  
pp. G344-G353 ◽  
Author(s):  
F. Gary Toback ◽  
Margaret M. Walsh-Reitz ◽  
Mark W. Musch ◽  
Eugene B. Chang ◽  
John Del Valle ◽  
...  

Antrum mucosal protein (AMP)-18 is a novel 18-kDa protein synthesized by cells of the gastric antrum mucosa. The protein is present in secretion granules of murine gastric antrum epithelial cells and is a component of canine antrum mucus, suggesting that it is secreted into the viscoelastic gel layer on the mucosal surface. Release of the protein appears to be regulated because forskolin decreased the amount of immunoreactive AMP-18 in primary cultures of canine antrum mucosal epithelial cells, and indomethacin gavaged into the stomach of mice reduced AMP-18 content in antrum mucosal tissue before inducing histological injury. A functional domain of the protein was identified by preparing peptides derived from the center of human AMP-18. A 21-mer peptide stimulated growth of gastric and intestinal epithelial cells, but not fibroblasts, and increased restitution of scrape-wounded gastric epithelial monolayers. These functions of AMP-18 suggest that its release onto the apical cell surface is regulated and that the protein and/or peptide fragments may protect the antral mucosa and promote healing by facilitating restitution and proliferation after injury.


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