scholarly journals Role of Actin Filament Network in Burkholderia multivorans Invasion in Well-Differentiated Human Airway Epithelia

2003 ◽  
Vol 71 (11) ◽  
pp. 6607-6609 ◽  
Author(s):  
Ute E. Schwab ◽  
Carla M. P. Ribeiro ◽  
Heiner Neubauer ◽  
Richard C. Boucher
Keyword(s):  
Biofilm Formation ◽  
Cell Entry ◽  
Airway Epithelia ◽  
Burkholderia Multivorans ◽  
Human Airway ◽  
Internalization Process ◽  
Well Differentiated ◽  
Filament Network ◽  
Human Airway Epithelia

ABSTRACT The role of the actin-based cytoskeleton in the internalization process of Burkholderia multivorans by well-differentiated human airway epithelia was investigated by immunohistology and confocal microscopy. Our data suggest that an intact actin cytoskeleton is required for biofilm formation but not single cell entry or paracytosis.

scholarly journals Endotoxin responsiveness of human airway epithelia is limited by low expression of MD-2

2004 ◽  
Vol 287 (2) ◽  
pp. L428-L437 ◽  
Author(s):  
Hong Peng Jia ◽  
Joel N. Kline ◽  
Andrea Penisten ◽  
Michael A. Apicella ◽  
Theresa L. Gioannini ◽  
...  
Keyword(s):  
Primary Cultures ◽  
Airway Epithelial Cells ◽  
Response To Treatment ◽  
Airway Epithelial ◽  
Airway Epithelia ◽  
Human Airway ◽  
Tnf Α ◽  
Pulmonary Macrophages ◽  
Well Differentiated ◽  
Human Airway Epithelia

The expression of inducible antimicrobial peptides, such as human β-defensin-2 (HBD-2) by epithelia, comprises a component of innate pulmonary defenses. We hypothesized that HBD-2 induction in airway epithelia is linked to pattern recognition receptors such as the Toll-like receptors (TLRs). We found that primary cultures of well-differentiated human airway epithelia express the mRNA for TLR-4, but little or no MD-2 mRNA, and display little HBD-2 expression in response to treatment with purified endotoxin ± LPS binding protein (LBP) and soluble CD14. Expression of endogenous MD-2 by transduction of airway epithelial cells with an adenoviral vector encoding MD-2 or extracellular addition of recombinant MD-2 both increased the responses of airway epithelia to endotoxin + LBP and sCD14 by >100-fold, as measured by NF-κB-luciferase activity and HBD-2 mRNA expression. MD-2 mRNA could be induced in airway epithelia by exposure of these cells to specific bacterial or host products (e.g., killed Haemophilus influenzae, the P6 outer membrane protein from H. influenzae, or TNF-α + IFN-γ). These findings suggest that MD-2, either coexpressed with TLR-4 or secreted when produced in excess of TLR-4 from neighboring cells, is required for airway epithelia to respond sensitively to endotoxin. The regulation of MD-2 expression in airway epithelia and pulmonary macrophages may serve as a means to modify endotoxin responsiveness in the airway.

scholarly journals Role of KVLQT1 in Cyclic Adenosine Monophosphate–Mediated Cl−Secretion in Human Airway Epithelia

2000 ◽  
Vol 23 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Marcus Mall ◽  
Andreas Wissner ◽  
Rainer Schreiber ◽  
Joachim Kuehr ◽  
Hans H. Seydewitz ◽  
...  
Keyword(s):  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Airway Epithelia ◽  
Cl Secretion ◽  
Human Airway ◽  
Human Airway Epithelia

scholarly journals The Mitochondrial Barriers Segregate Agonist-induced Calcium-dependent Functions in Human Airway Epithelia

2003 ◽  
Vol 122 (4) ◽  
pp. 377-387 ◽  
Author(s):  
Carla M. Pedrosa Ribeiro ◽  
Anthony M. Paradiso ◽  
Alessandra Livraghi ◽  
Richard C. Boucher
Keyword(s):  
Purinergic Receptor ◽  
Basolateral Membrane ◽  
Receptor Activation ◽  
Airway Epithelial ◽  
Airway Epithelia ◽  
Cl Secretion ◽  
Epithelial Monolayers ◽  
Human Airway ◽  
Human Airway Epithelia

In airway epithelia, purinergic receptor (P2Y2-R) stimulation of intracellular calcium (Ca2+i)–regulated ion transport is restricted to the membrane domain ipsilateral to receptor activation, implying compartmentalization of Ca2+i signaling. Because mitochondria can spatially restrict cellular Ca2+i signals, immunocytochemical, electron microscopic, and fluorescent studies of mitochondria localization were performed in human airway epithelia. Although concentrated at the apical domain, mitochondria were found distributed at both the apical and the basolateral poles and in close association with the endoplasmic reticulum. The role of mitochondria in locally restricting P2Y2-R–induced Ca2+i signals was investigated by measuring changes in mitochondrial Ca2+ (Ca2+m) in human airway epithelial monolayers. P2Y2-R activation induced Ca2+m accumulation in mitochondria confined to the domain ipsilateral to P2Y2-R stimulation, which was blocked by mitochondrial uncoupling with 1 μM CCCP and 2.5 μg/ml oligomycin. The role of mitochondria in restricting the cellular cross-talk between basolateral P2Y2-R–dependent Ca2+i mobilization and apical membrane Ca2+-activated Cl− secretion was investigated in studies simultaneously measuring Ca2+i and Cl− secretion in cystic fibrosis human airway epithelial monolayers. Activation of basolateral P2Y2-Rs produced similar increases in Ca2+i in monolayers without and with pretreatment with uncouplers, whereas Ca2+i-activated Cl− secretion was only efficiently triggered in mitochondria-uncoupled conditions. We conclude that (a) mitochondria function as a Ca2+i-buffering system in airway epithelia, compartmentalizing Ca2+i-dependent functions to the membrane ipsilateral to receptor stimulation; and (b) the mitochondria provide structural barriers that protect the airway epithelia against nonspecific activation of Ca2+i-modulated functions associated with Ca2+i signals emanating from the apical or the basolateral membrane domains.

scholarly journals ACE2 Receptor Expression and Severe Acute Respiratory Syndrome Coronavirus Infection Depend on Differentiation of Human Airway Epithelia

2005 ◽  
Vol 79 (23) ◽  
pp. 14614-14621 ◽  
Author(s):  
Hong Peng Jia ◽  
Dwight C. Look ◽  
Lei Shi ◽  
Melissa Hickey ◽  
Lecia Pewe ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Receptor Expression ◽  
Pseudotyped Virus ◽  
Apical Surface ◽  
Sars Coronavirus ◽  
Airway Epithelia ◽  
S Protein ◽  
Human Airway ◽  
Well Differentiated ◽  
Human Airway Epithelia

ABSTRACT Studies of patients with severe acute respiratory syndrome (SARS) demonstrate that the respiratory tract is a major site of SARS-coronavirus (CoV) infection and disease morbidity. We studied host-pathogen interactions using native lung tissue and a model of well-differentiated cultures of primary human airway epithelia. Angiotensin converting enzyme 2 (ACE2), the receptor for both the SARS-CoV and the related human respiratory coronavirus NL63, was expressed in human airway epithelia as well as lung parenchyma. As assessed by immunofluorescence staining and membrane biotinylation, ACE2 protein was more abundantly expressed on the apical than the basolateral surface of polarized airway epithelia. Interestingly, ACE2 expression positively correlated with the differentiation state of epithelia. Undifferentiated cells expressing little ACE2 were poorly infected with SARS-CoV, while well-differentiated cells expressing more ACE2 were readily infected. Expression of ACE2 in poorly differentiated epithelia facilitated SARS spike (S) protein-pseudotyped virus entry. Consistent with the expression pattern of ACE2, the entry of SARS-CoV or a lentivirus pseudotyped with SARS-CoV S protein in differentiated epithelia was more efficient when applied to the apical surface. Furthermore, SARS-CoV replicated in polarized epithelia and preferentially exited via the apical surface. The results indicate that infection of human airway epithelia by SARS coronavirus correlates with the state of cell differentiation and ACE2 expression and localization. These findings have implications for understanding disease pathogenesis associated with SARS-CoV and NL63 infections.

KGF alters gene expression in human airway epithelia: potential regulation of the inflammatory response

2001 ◽  
Vol 6 (2) ◽  
pp. 81-89 ◽  
Author(s):  
LAWRENCE S. PRINCE ◽  
PHILIP H. KARP ◽  
THOMAS O. MONINGER ◽  
MICHAEL J. WELSH
Keyword(s):  
Keratinocyte Growth Factor ◽  
Primary Cultures ◽  
Airway Epithelia ◽  
Altered Expression ◽  
Human Airway ◽  
Gene Transcripts ◽  
Induced Genes ◽  
Well Differentiated ◽  
Cf Transmembrane Conductance Regulator ◽  
Human Airway Epithelia

Keratinocyte growth factor (KGF) regulates several functions in adult and developing lung epithelia; it causes proliferation, stimulates secretion of fluid and electrolytes, enhances repair, and may minimize injury. To gain insight into the molecular processes influenced by KGF, we applied KGF to primary cultures of well-differentiated human airway epithelia and used microarray hybridization to assess the abundance of gene transcripts. Of 7,069 genes tested, KGF changed expression levels of 910. Earlier studies showed that KGF causes epithelial proliferation, and as expected, treatment altered expression of numerous genes involved in cell proliferation. We found that KGF stimulated transepithelial Cl−transport, but the number of cystic fibrosis (CF) transmembrane conductance regulator (CFTR) transcripts fell. Although transcripts for ClC-1 and ClC-7 Cl−channels increased, KGF failed to augment transepithelial Cl−transport in CF epithelia, suggesting that KGF-stimulated Cl−transport in differentiated airway epithelia depends on the CFTR Cl−channel. Interestingly, KGF decreased transcripts for many interferon (IFN)-induced genes. IFN causes trafficking of Stat dimers to the nucleus, where they activate transcription of IFN-induced genes. We found that KGF prevented the IFN-stimulated trafficking of Stat1 from the cytosol to the nucleus, suggesting a molecular mechanism for KGF-mediated suppression of the IFN-signaling pathway. These results suggest that in addition to stimulating proliferation and repair of damaged airway epithelia, KGF stimulates Cl−transport and may dampen the response of epithelial cells to inflammatory mediators.

Basolateral chloride current in human airway epithelia

2007 ◽  
Vol 293 (4) ◽  
pp. L991-L999 ◽  
Author(s):  
Omar A. Itani ◽  
Fred S. Lamb ◽  
James E. Melvin ◽  
Michael J. Welsh
Keyword(s):  
Cystic Fibrosis ◽  
Signaling Pathways ◽  
Basolateral Membrane ◽  
Primary Cultures ◽  
Cell Swelling ◽  
Disulfonic Acid ◽  
Airway Epithelia ◽  
Human Airway ◽  
Well Differentiated ◽  
Human Airway Epithelia

Electrolyte transport by airway epithelia regulates the quantity and composition of liquid covering the airways. Previous data indicate that airway epithelia can absorb NaCl. At the apical membrane, cystic fibrosis transmembrane conductance regulator (CFTR) provides a pathway for Cl− absorption. However, the pathways for basolateral Cl− exit are not well understood. Earlier studies, predominantly in cell lines, have reported that the basolateral membrane contains a Cl− conductance. However, the properties have varied substantially in different epithelia. To better understand the basolateral Cl− conductance in airway epithelia, we studied primary cultures of well-differentiated human airway epithelia. The basolateral membrane contained a Cl− current that was inhibited by 4,4′-diisothiocyanostilbene-2,2′-disulfonic acid (DIDS). The current-voltage relationship was nearly linear, and the halide selectivity was Cl− > Br− >> I−. Several signaling pathways increased the current, including elevation of cellular levels of cAMP, activation of protein kinase C (PKC), and reduction of pH. In contrast, increasing cell Ca2+ and inducing cell swelling had no effect. The basolateral Cl− current was present in both cystic fibrosis (CF) and non-CF airway epithelia. Likewise, airway epithelia from wild-type mice and mice with disrupted genes for ClC-2 or ClC-3 all showed similar Cl− currents. These data suggest that the basolateral membrane of airway epithelia possesses a Cl− conductance that is not due to CFTR, ClC-2, or ClC-3. Its regulation by cAMP and PKC signaling pathways suggests that coordinated regulation of Cl− conductance in both apical and basolateral membranes may be important in controlling transepithelial Cl− movement.

scholarly journals Azithromycin Treatment Alters Gene Expression in Inflammatory, Lipid Metabolism, and Cell Cycle Pathways in Well-Differentiated Human Airway Epithelia

PLoS ONE ◽  
2009 ◽  
Vol 4 (6) ◽  
pp. e5806 ◽  
Author(s):  
Carla Maria P. Ribeiro ◽  
Harry Hurd ◽  
Yichao Wu ◽  
Mary E. B. Martino ◽  
Lisa Jones ◽  
...  
Keyword(s):  
Gene Expression ◽  
Cell Cycle ◽  
Lipid Metabolism ◽  
Airway Epithelia ◽  
Human Airway ◽  
Well Differentiated ◽  
Human Airway Epithelia
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