scholarly journals Cdc42 Regulates Apical Junction Formation in Human Bronchial Epithelial Cells through PAK4 and Par6B

2010 ◽  
Vol 21 (17) ◽  
pp. 2996-3006 ◽  
Author(s):  
Sean W. Wallace ◽  
Joanne Durgan ◽  
Dan Jin ◽  
Alan Hall
Keyword(s):  
Epithelial Cells ◽  
Apical Cell ◽  
Lung Epithelial Cells ◽  
Cell Junctions ◽  
Epithelial Cell Line ◽  
Dependent Manner ◽  
Bronchial Epithelial ◽  
Junction Formation ◽  
Apical Junctions ◽  
Cell Cell

Cdc42 has been implicated in numerous biochemical pathways during epithelial morphogenesis, including the control of spindle orientation during mitosis, the establishment of apical-basal polarity, the formation of apical cell–cell junctions, and polarized secretion. To investigate the signaling pathways through which Cdc42 mediates these diverse effects, we have screened an siRNA library corresponding to the 36 known Cdc42 target proteins, in a human bronchial epithelial cell line. Two targets, PAK4 and Par6B, were identified as necessary for the formation of apical junctions. PAK4 is recruited to nascent cell–cell contacts in a Cdc42-dependent manner, where it is required for the maturation of primordial junctions into apical junctions. PAK4 kinase activity is essential for junction maturation, but overexpression of an activated PAK4 mutant disrupts this process. Par6B, together with its binding partner aPKC, is necessary both for junction maturation and for the retention of PAK4 at sites of cell–cell contact. This study demonstrates that controlled regulation of PAK4 is required for apical junction formation in lung epithelial cells and highlights potential cross-talk between two Cdc42 targets, PAK4 and Par6B.

Mitogen-activated protein kinases mediate peroxynitrite-induced cell death in human bronchial epithelial cells

2003 ◽  
Vol 284 (6) ◽  
pp. L1112-L1120 ◽  
Author(s):  
Elodie Nabeyrat ◽  
Gina E. Jones ◽  
Peter S. Fenwick ◽  
Peter J. Barnes ◽  
Louise E. Donnelly
Keyword(s):  
Cell Death ◽  
Epithelial Cells ◽  
Protein Kinases ◽  
Lung Epithelial Cells ◽  
Epithelial Cell Line ◽  
Dependent Manner ◽  
Bronchial Epithelial ◽  
Mitogen Activated Protein Kinases ◽  
Mitogen Activated Protein ◽  
Sb 239063

Peroxynitrite, formed by the reaction of nitric oxide (NO · ) with superoxide anions (O[Formula: see text]·), may play a role in the pathophysiology of inflammation. The effects of 3-morpholinosydnonimine (SIN-1), a peroxynitrite generator, on the human bronchial epithelial cell line BEAS-2B, were examined. SIN-1 exposure resulted in cell death in a time- and dose-dependent manner. Depletion of intracellular glutathione increased the vulnerability of the cells. Pretreatment with Mn(III)tetrakis( N-methyl-4′-pyridyl)porphyrin (MnTMPyP) or hydroxocobalamin (HC), O[Formula: see text]· and NO · scavengers, respectively, reduced significantly SIN-1-induced cell death (18.66 ± 3.57 vs. 77.01 ± 14.07 or 82.20 ± 9.64, % cell viability SIN-1 vs. MnTMPyP or HC). Moreover, the mitogen-activated protein kinases (MAPK) p44/42 (ERK), p38, and p54/46 (JNK) were also activated in a time- and concentration-dependent manner. PD-98059 and SB-239063, specific inhibitors of ERK and p38 MAPK pathways, failed to protect cells against 1 mM SIN-1. However, PD-98059 partially inhibited (60% cell survival) SIN-1 effects at ≤0.25 mM, and this was increased with the inclusion of SB-239063. Therefore, MAPKs may mediate signal transduction pathways induced by peroxynitrite in lung epithelial cells leading to cell death.

15-Lipoxygenase-1 induces expression and release of chemokines in cultured human lung epithelial cells

2009 ◽  
Vol 297 (1) ◽  
pp. L196-L203 ◽  
Author(s):  
Cheng Liu ◽  
Dawei Xu ◽  
Li Liu ◽  
Frida Schain ◽  
Åsa Brunnström ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Human Lung ◽  
A549 Cells ◽  
Airway Epithelial Cells ◽  
Bronchial Epithelial Cells ◽  
Lung Epithelial Cells ◽  
Epithelial Cell Line ◽  
Chronic Obstructive ◽  
Bronchial Epithelial ◽  
Lung Epithelial

15-Lipoxygenase-1 (15-LOX-1) has been proposed to be involved in various physiological and pathophysiological activities such as inflammation, atherosclerosis, cell maturation, and tumorigenesis. Asthma and chronic obstructive pulmonary disease are associated with increased expression of 15-LOX-1 in bronchial epithelial cells, but the potential functions of 15-LOX-1 in airway epithelial cells have not been well clarified. To study the function of 15-LOX-1 in bronchial epithelial cells, we ectopically expressed 15-LOX-1 in the human lung epithelial cell line A549. We found that overexpression of 15-LOX-1 in A549 cells leads to increased release of the chemokines MIP-1α, RANTES, and IP-10, and thereby to increased recruitment of immature dendritic cells, mast cells, and activated T cells. These results suggest that an increased expression and activity of 15-LOX-1 in lung epithelial cells is a proinflammatory event in the pathogenesis of asthma and other inflammatory lung disorders.

scholarly journals Heat Shock Protein 27 Associates with Basolateral Cell Boundaries in Heat-Shocked and ATP-Depleted Epithelial Cells

2002 ◽  
Vol 13 (2) ◽  
pp. 332-341
Author(s):  
Eric A. Shelden ◽  
Michael J. Borrelli ◽  
Fiona M. Pollock ◽  
Rita Bonham
Keyword(s):  
Heat Stress ◽  
Heat Shock ◽  
Epithelial Cells ◽  
Apical Cell ◽  
Atp Depletion ◽  
Cell Junctions ◽  
Cell Contact ◽  
Double Labeling ◽  
Cell Substrate ◽  
Cell Cell

ABSTRACT. Heat stress alters epithelial barrier function, and heat stress preconditioning protects epithelial function from injury. Hsp27 is a small stress protein that has previously been shown to modulate actin assembly. Thus, by regulating actin filaments associated with cell junctions, hsp27 could alter epithelial function. To begin to address this hypothesis, the regulation and distribution of a human hsp27-green fluorescence fusion protein (EGFPhHsp27) that is expressed in cultured renal epithelial cells was assessed. EGFPhHsp27, like the endogenous hsp27, associated with the cytoskeleton in heat-stressed and chemically ATP-depleted cells, and both proteins were regulated similarly. Confocal microscopy of intact and detergent-lysed cells revealed novel distribution patterns in which EGFPhHsp27 associated with basolateral, but not apical, cell borders in injured cells. Double labeling studies revealed EGFPhHsp27 and actin filament colocalization in ATP-depleted cells. However, during heat shock, granules of EGFPhHsp27 were found at sites of cell-cell contact and in the cell body, but colocalization with actin was not apparent. Thus, heat stress and ATP depletion induce distinct patterns of hsp27 redistribution in epithelial cells, and sites of cell-cell and cell-substrate attachment are unique in their ability to recruit hsp27 during injury. The association of EGFPhHsp27 with basolateral cell boundaries supports a potential role for hsp27 in protection or regulation of epithelial cell-cell and cell-substrate attachments.

scholarly journals Adherence of Streptococcus pneumoniae to Human Bronchial Epithelial Cells (BEAS-2B)

1998 ◽  
Vol 66 (2) ◽  
pp. 820-822 ◽  
Author(s):  
John E. Adamou ◽  
Theresa M. Wizemann ◽  
Philip Barren ◽  
Solomon Langermann
Keyword(s):  
Streptococcus Pneumoniae ◽  
Epithelial Cells ◽  
Cell Line ◽  
Pneumococcal Infection ◽  
Bronchial Epithelium ◽  
Bronchial Epithelial Cells ◽  
Alveolar Epithelial Cells ◽  
Epithelial Cell Line ◽  
Dependent Manner ◽  
Bronchial Epithelial

ABSTRACT Pneumococcal adherence to alveolar epithelial cells and nasopharyngeal epithelial cells has been well characterized. However, the interaction of Streptococcus pneumoniae with bronchial epithelial cells has not been studied. We have now shown that pneumococci bind specifically to a human bronchial epithelial cell line (BEAS-2B cells). Pneumococci adhered to BEAS-2B cells in a time- and dose-dependent manner. These results suggest that the bronchial epithelium may serve as an additional site of attachment for pneumococci and demonstrate the utility of the BEAS-2B cell line for studying mechanisms of pneumococcal infection.

scholarly journals Oral Primo-Colonizing Bacteria Modulate Inflammation and Gene Expression in Bronchial Epithelial Cells

2020 ◽  
Vol 8 (8) ◽  
pp. 1094
Author(s):  
Elliot Mathieu ◽  
Chad W. MacPherson ◽  
Jocelyn Belvis ◽  
Olivier Mathieu ◽  
Véronique Robert ◽  
...  
Keyword(s):  
Gene Expression ◽  
Epithelial Cells ◽  
Oral Cavity ◽  
Bronchial Epithelial Cell ◽  
Bronchial Epithelial Cells ◽  
Lung Epithelial Cells ◽  
Epithelial Cell Line ◽  
Global Changes ◽  
Bronchial Epithelial ◽  
Specific Effects

The microbiota of the mouth disperses into the lungs, and both compartments share similar phyla. Considering the importance of the microbiota in the maturation of the immunity and physiology during the first days of life, we hypothesized that primo-colonizing bacteria of the oral cavity may induce immune responses in bronchial epithelial cells. Herein, we have isolated and characterized 57 strains of the buccal cavity of two human newborns. These strains belong to Streptococcus, Staphylococcus, Enterococcus, Rothia and Pantoea genera, with Streptococcus being the most represented. The strains were co-incubated with a bronchial epithelial cell line (BEAS-2B), and we established their impact on a panel of cytokines/chemokines and global changes in gene expression. The Staphylococcus strains, which appeared soon after birth, induced a high production of IL-8, suggesting they can trigger inflammation, whereas the Streptococcus strains were less associated with inflammation pathways. The genera Streptococcus, Enterococcus and Pantoea induced differential profiles of cytokine/chemokine/growth factor and set of genes associated with maturation of morphology. Altogether, our results demonstrate that the microorganisms, primo-colonizing the oral cavity, impact immunity and morphology of the lung epithelial cells, with specific effects depending on the phylogeny of the strains.

scholarly journals Lulu2 regulates the circumferential actomyosin tensile system in epithelial cells through p114RhoGEF

2011 ◽  
Vol 195 (2) ◽  
pp. 245-261 ◽  
Author(s):  
Hiroyuki Nakajima ◽  
Takuji Tanoue
Keyword(s):  
Epithelial Cells ◽  
Cell Shape ◽  
Molecular Mechanisms ◽  
Molecular System ◽  
Apical Cell ◽  
Cell Junctions ◽  
Cellular Processes ◽  
Kinase C ◽  
Important Regulator ◽  
Cell Cell

Myosin II–driven mechanical forces control epithelial cell shape and morphogenesis. In particular, the circumferential actomyosin belt, which is located along apical cell–cell junctions, regulates many cellular processes. Despite its importance, the molecular mechanisms regulating the belt are not fully understood. In this paper, we characterize Lulu2, a FERM (4.1 protein, ezrin, radixin, moesin) domain–containing molecule homologous to Drosophila melanogaster Yurt, as an important regulator. In epithelial cells, Lulu2 is localized along apical cell–cell boundaries, and Lulu2 depletion by ribonucleic acid interference results in disorganization of the circumferential actomyosin belt. In its regulation of the belt, Lulu2 interacts with and activates p114RhoGEF, a Rho-specific guanine nucleotide exchanging factor (GEF), at apical cell–cell junctions. This interaction is negatively regulated via phosphorylation events in the FERM-adjacent domain of Lulu2 catalyzed by atypical protein kinase C. We further found that Patj, an apical cell polarity regulator, recruits p114RhoGEF to apical cell–cell boundaries via PDZ (PSD-95/Dlg/ZO-1) domain–mediated interaction. These findings therefore reveal a novel molecular system regulating the circumferential actomyosin belt in epithelial cells.

Microtubule dynamics and Rac-1 signaling independently regulate barrier function in lung epithelial cells

2007 ◽  
Vol 293 (5) ◽  
pp. L1321-L1331 ◽  
Author(s):  
Magdalena J. Lorenowicz ◽  
Mar Fernandez-Borja ◽  
Anne-Marieke D. van Stalborch ◽  
Marian A. J. A. van Sterkenburg ◽  
Pieter S. Hiemstra ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Epithelial Cells ◽  
Barrier Function ◽  
Lung Epithelial Cells ◽  
Cell Junctions ◽  
Epithelial Barrier ◽  
Cell Contact ◽  
Epithelial Barrier Function ◽  
Lung Epithelial ◽  
Cell Cell

Cadherin-mediated cell-cell adhesion controls the morphology and function of epithelial cells and is a critical component of the pathology of chronic inflammatory disorders. Dynamic interactions between cadherins and the actin cytoskeleton are required for stable cell-cell contact. Besides actin, microtubules also target intercellular, cadherin-based junctions and contribute to their formation and stability. Here, we studied the role of microtubules in conjunction with Rho-like GTPases in the regulation of lung epithelial barrier function using real-time monitoring of transepithelial electrical resistance. Unexpectedly, we found that disruption of microtubules promotes epithelial cell-cell adhesion. This increase in epithelial barrier function is accompanied by the accumulation of β-catenin at cell-cell junctions, as detected by immunofluorescence. Moreover, we found that the increase in cell-cell contact, induced by microtubule depolymerization, requires signaling through a RhoA/Rho kinase pathway. The Rac-1 GTPase counteracts this pathway, because inhibition of Rac-1 signaling rapidly promotes epithelial barrier function, in a microtubule- and RhoA-independent fashion. Together, our data suggest that microtubule-RhoA-mediated signaling and Rac-1 control lung epithelial integrity through counteracting independent pathways.

scholarly journals STING Mediates Cytosolic Dna-Induced Muc5ac Mrna Expression in Human Bronchial Epithelial Cells

2020 ◽  
Author(s):  
Masaya Ohta ◽  
Yutaka Nishida ◽  
Hisako Yagi ◽  
Aikira Aizawa ◽  
Takahito Oyanagi ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Mrna Expression ◽  
Cell Types ◽  
Bronchial Epithelial Cells ◽  
Epithelial Cell Line ◽  
Mrna Levels ◽  
Dependent Manner ◽  
Dna Sensing ◽  
Human Bronchial Epithelial Cells ◽  
Bronchial Epithelial

Abstract Background: Non-autologous and autologous cytosolic DNA are recognized as danger signals by cytoplasmic sensor molecules that activate signal-transduction pathways. An important molecule in cytosolic DNA sensing is stimulator of interferon genes (STING), an endoplasmic reticulum protein activated by cyclic GMP–AMP (cGAMP) produced in response to cytosolic DNA. STING is important for innate immune responses to cytosolic DNA in immune cells; however, knowledge about its role in bronchial epithelial cells is limited. Methods: We stimulated NCI-H292 cells with poly(dA:dT) and silenced STING and other regulatory proteins, and then determined MUC5AC mRNA expression levels. Results: Cytosolic DNA increased the expression of a major respiratory mucin protein, MUC5AC, in the human respiratory epithelial cell line NCI-H292 in a STING-dependent manner. Introducing poly(dA:dT) into the cytoplasm induced MUC5AC and interferon-β (IFNβ) expression. Silencing STING by RNA interference decreased poly(dA:dT)-induced MUC5AC mRNA expression but increased IFN-β mRNA levels. Furthermore, cGAMP treatment increased MUC5AC expression but not IFN-β expression. In contrast, silencing retinoic acid-inducible gene-I (RIG-I), which is a component of a different nucleic acid-sensing system, suppressed poly(dA:dT)-induced IFN-β expression and increased MUC5AC expression. Conclusions: Unlike its role in other cell types, in human bronchial epithelial cells, STING is central to cytosolic DNA-induced MUC5AC expression, whereas IFN-β expression is dependent on RIG-I. Our data indicate a functional interaction between the STING and RIG-I pathways, suggesting the existence of intricate and cell-specific cytosolic DNA-sensing systems.

scholarly journals DAPLE and MPDZ bind to each other and cooperate to promote apical cell constriction

2019 ◽  
Vol 30 (16) ◽  
pp. 1900-1910 ◽  
Author(s):  
Arthur Marivin ◽  
Mikel Garcia-Marcos
Keyword(s):  
G Protein ◽  
Cultured Cells ◽  
Apical Cell ◽  
Cell Junctions ◽  
Binding Motif ◽  
Apical Constriction ◽  
Protein Activation ◽  
Neuroepithelial Cells ◽  
Two Factors ◽  
Apical Junctions

Dishevelled-Associating Protein with a high frequency of LEucines (DAPLE) belongs to a group of unconventional activators of heterotrimeric G-proteins that are cytoplasmic factors rather than membrane proteins of the G-protein–coupled receptor superfamily. During neurulation, DAPLE localizes to apical junctions of neuroepithelial cells and promotes apical cell constriction via G-protein activation. While junctional localization of DAPLE is necessary for this function, the factors it associates with at apical junctions or how they contribute to DAPLE-mediated apical constriction are unknown. MPDZ is a multi-PDZ (PSD95/DLG1/ZO-1) domain scaffold present at apical cell junctions whose mutation in humans is linked to nonsyndromic congenital hydrocephalus (NSCH). DAPLE contains a PDZ-binding motif (PBM) and is also mutated in human NSCH, so we investigated the functional relationship between both proteins. DAPLE colocalized with MPDZ at apical cell junctions and bound directly to the PDZ3 domain of MPDZ via its PBM. Much like DAPLE, MPDZ is induced during neurulation in Xenopus and is required for apical constriction of neuroepithelial cells and subsequent neural plate bending. MPDZ depletion also blunted DAPLE-­mediated apical constriction of cultured cells. These results show that DAPLE and MPDZ, two factors genetically linked to NSCH, function as cooperative partners at apical junctions and are required for proper tissue remodeling during early stages of neurodevelopment.

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