scholarly journals Effects of cigarette smoke on barrier function and tight junction proteins in the bronchial epithelium: protective role of cathelicidin LL-37

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Miyoko Tatsuta ◽  
Keiko Kan-o ◽  
Yumiko Ishii ◽  
Norio Yamamoto ◽  
Tomohiro Ogawa ◽  
...  
Keyword(s):  
Protein Expression ◽  
Cigarette Smoke ◽  
Barrier Function ◽  
Bronchial Epithelium ◽  
Epithelial Barrier ◽  
Airway Epithelial ◽  
Barrier Dysfunction ◽  
Expression Levels ◽  
Gene And Protein Expression ◽  
Epithelial Barrier Dysfunction

Abstract Background Airway epithelial barrier function is maintained by the formation of tight junctions (TJs) and adherens junctions (AJs). Inhalation of cigarette smoke causes airway epithelial barrier dysfunction and may contribute to the pathogenesis of chronic lung diseases such as asthma and chronic obstructive pulmonary disease (COPD). We assessed the effects of cigarette smoke on barrier function and expression of multiple TJ and AJ proteins in the bronchial epithelium. We also examined whether treatment with glucocorticosteroids (GCSs), long-acting β2-agonists (LABAs), and human cathelicidin LL-37 can protect against cigarette smoke extract (CSE)-induced barrier dysfunction. Methods Calu-3 cells cultured at the air-liquid interface were pretreated with or without GCSs, LABAs, GCSs plus LABAs, or LL-37, and subsequently exposed to CSE. Barrier function was assessed by transepithelial electronic resistance (TEER) measurements. Gene and protein expression levels of TJ and AJ proteins were analyzed by quantitative PCR and western blotting, respectively. Immunofluorescence staining of TJ and AJ proteins was performed. Results CSE decreased TEER and increased permeability in a concentration-dependent manner. CSE suppressed gene expression of claudin-1, claudin-3, claudin-4, claudin-7, claudin-15, occludin, E-cadherin, junctional adhesion molecule-A (JAM-A) and zonula occludens-1 (ZO-1) within 12 h post-CSE exposure, while suppressed protein expression levels of occludin at 12 h. CSE-treated cells exhibited discontinuous or attenuated immunostaining for claudin-1, claudin-3, claudin-4, occludin, ZO-1, and E-cadherin compared with untreated cells. GCS treatment partially restored CSE-induced TEER reduction, while LABA treatment had no effect. GCS and LABA combination treatment had no additive effect on CSE-induced TEER reduction and gene suppression of TJ and AJ proteins. Human cathelicidin LL-37 counteracted CSE-induced TEER reduction and prevented disruption of occludin and ZO-1. LL-37 also attenuated CSE-induced decreases in gene and protein expression levels of occludin. Conclusions CSE caused airway epithelial barrier dysfunction and simultaneously downregulated multiple TJ and AJ proteins. GCS and LABA combination treatment had no additive effect on CSE-induced TEER reduction. LL-37 counteracted CSE-induced TEER reduction and prevented disruption of occludin and ZO-1. Use of LL-37 to counteract airway epithelial barrier dysfunction may have significant benefits for respiratory diseases such as asthma and COPD.

scholarly journals The role of secreted Hsp90α in HDM-induced asthmatic airway epithelial barrier dysfunction

2019 ◽  
Vol 19 (1) ◽  
Author(s):  
Cuiping Ye ◽  
Chaowen Huang ◽  
Mengchen Zou ◽  
Yahui Hu ◽  
Lishan Luo ◽  
...  
Keyword(s):  
Barrier Function ◽  
Epithelial Barrier ◽  
Airway Epithelial ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Function ◽  
Asthmatic Airway ◽  
Epithelial Barrier Dysfunction

Abstract Background The dysfunction of airway epithelial barrier is closely related to the pathogenesis of asthma. Secreted Hsp90α participates in inflammation and Hsp90 inhibitor protects endothelial dysfunction. In the current study, we aimed to explore the role of secreted Hsp90α in asthmatic airway epithelial barrier function. Methods Male BALB/c mice were sensitized and challenged with HDM to generate asthma model. The 16HBE and Hsp90α-knockdown cells were cultured and treated according to the experiment requirements. Transepithelial Electric Resistance (TEER) and permeability of epithelial layer in vitro, distribution and expression of junction proteins both in vivo and in vitro were used to evaluate the epithelial barrier function. Western Blot was used to evaluate the expression of junction proteins and phosphorylated AKT in cells and lung tissues while ELISA were used to evaluate the Hsp90α expression and cytokines release in the lung homogenate. Results HDM resulted in a dysfunction of airway epithelial barrier both in vivo and in vitro, paralleled with the increased expression and release of Hsp90α. All of which were rescued in Hsp90α-knockdown cells or co-administration of 1G6-D7. Furthermore, either 1G6-D7 or PI3K inhibitor LY294002 suppressed the significant phosphorylation of AKT, which caused by secreted and recombinant Hsp90α, resulting in the restoration of epithelial barrier function. Conclusions Secreted Hsp90α medicates HDM-induced asthmatic airway epithelial barrier dysfunction via PI3K/AKT pathway, indicating that anti-secreted Hsp90α therapy might be a potential treatment to asthma in future.

Proteolytic antigens interfere with endosome/lysosome fusion in epithelial cells

2013 ◽  
Vol 91 (6) ◽  
pp. 449-454 ◽  
Author(s):  
Yu-Wei Liao ◽  
Xing-Mao Wu ◽  
Jia Jia ◽  
Xiao-Lei Wu ◽  
Hong Tao ◽  
...  
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Cell Line ◽  
Barrier Function ◽  
Epithelial Barrier ◽  
Epithelial Cell Line ◽  
Airway Epithelial ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Function ◽  
Epithelial Barrier Dysfunction

The airway epithelial barrier function is important in maintaining the homeostasis in the body. A number of airway disorders are associated with the epithelial barrier dysfunction. The present study aims to elucidate a possible mechanism by which the proteolytic allergens compromise the epithelial barrier function. The airway epithelial cell line, RPMI 2650 cells (Rp cells) and kidney epithelial cell line, MDCK cells, were cultured to be monolayers and used as an in vitro epithelial barrier model. House dust mite antigen, Der P1 (Der) was used as an antigen that has the proteolytic property. The epithelial barrier permeability and transepithelial resistance (TER) were used as the indicators of epithelial barrier function. Both epithelial cell lines could endocytose Der in the culture. Some of the Der was transported across the epithelial barrier to the basal chambers of the Transwells without affecting the TER. The endocytic Der could suppress the expression of ubiquitin E3 lases A20 and further interfered with the fusion of endosome/lysosome in the epithelial cells. Mite antigen, Der, can interfere with the fusion of endosome/lysosome in epithelial cells to induce the epithelial barrier dysfunction.

scholarly journals PGC-1α mediates a metabolic host defense response in human airway epithelium during rhinovirus infections

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Aubrey N. Michi ◽  
Bryan G. Yipp ◽  
Antoine Dufour ◽  
Fernando Lopes ◽  
David Proud
Keyword(s):  
Host Defense ◽  
Barrier Function ◽  
Bacterial Infections ◽  
Molecular Mechanisms ◽  
Cellular Damage ◽  
Epithelial Barrier ◽  
Airway Epithelial ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Function ◽  
Epithelial Damage

AbstractHuman rhinoviruses (HRV) are common cold viruses associated with exacerbations of lower airways diseases. Although viral induced epithelial damage mediates inflammation, the molecular mechanisms responsible for airway epithelial damage and dysfunction remain undefined. Using experimental HRV infection studies in highly differentiated human bronchial epithelial cells grown at air-liquid interface (ALI), we examine the links between viral host defense, cellular metabolism, and epithelial barrier function. We observe that early HRV-C15 infection induces a transitory barrier-protective metabolic state characterized by glycolysis that ultimately becomes exhausted as the infection progresses and leads to cellular damage. Pharmacological promotion of glycolysis induces ROS-dependent upregulation of the mitochondrial metabolic regulator, peroxisome proliferator-activated receptor-γ coactivator 1α (PGC-1α), thereby restoring epithelial barrier function, improving viral defense, and attenuating disease pathology. Therefore, PGC-1α regulates a metabolic pathway essential to host defense that can be therapeutically targeted to rescue airway epithelial barrier dysfunction and potentially prevent severe respiratory complications or secondary bacterial infections.

scholarly journals Chymase-mediated intestinal epithelial permeability is regulated by a protease-activating receptor/matrix metalloproteinase-2-dependent mechanism

2013 ◽  
Vol 304 (5) ◽  
pp. G479-G489 ◽  
Author(s):  
Katherine R. Groschwitz ◽  
David Wu ◽  
Heather Osterfeld ◽  
Richard Ahrens ◽  
Simon P. Hogan
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Barrier Function ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
Intestinal Epithelial Barrier ◽  
Epithelial Barrier Function ◽  
Epithelial Barrier Dysfunction

Mast cells regulate intestinal barrier function during disease and homeostasis. Secretion of the mast cell-specific serine protease chymase regulates homeostasis. In the present study, we employ in vitro model systems to delineate the molecular pathways involved in chymase-mediated intestinal epithelial barrier dysfunction. Chymase stimulation of intestinal epithelial (Caco-2 BBe) cell monolayers induced a significant reduction in transepithelial resistance, indicating decreased intestinal epithelial barrier function. The chymase-induced intestinal epithelial barrier dysfunction was characterized by chymase-induced protease-activated receptor (PAR)-2 activation and matrix metalloproteinase (MMP)-2 expression and activation. Consistent with this observation, in vitro analysis revealed chymase-induced PAR-2 activation and increased MAPK activity and MMP-2 expression. Pharmacological and small interfering RNA-mediated antagonism of PAR-2 and MMP-2 significantly attenuated chymase-stimulated barrier dysfunction. Additionally, the chymase/MMP-2-mediated intestinal epithelial dysfunction was associated with a significant reduction in the tight junction protein claudin-5, which was partially restored by MMP-2 inhibition. Finally, incubation of Caco-2 BBe cells with chymase-sufficient, but not chymase-deficient, bone marrow-derived mast cells decreased barrier function, which was attenuated by the chymase inhibitor chymostatin. Collectively, these results suggest that mast cell/chymase-mediated intestinal epithelial barrier function is mediated by PAR-2/MMP-2-dependent pathways.

scholarly journals Titanium dioxide nanoparticles exaggerate respiratory syncytial virus-induced airway epithelial barrier dysfunction

2020 ◽  
Vol 319 (3) ◽  
pp. L481-L496
Author(s):  
Carrie C. Smallcombe ◽  
Terri J. Harford ◽  
Debra T. Linfield ◽  
Susana Lechuga ◽  
Vladimir Bokun ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
Respiratory Syncytial Virus ◽  
Titanium Dioxide Nanoparticles ◽  
Airway Disease ◽  
Epithelial Barrier ◽  
Airway Epithelial ◽  
Barrier Dysfunction ◽  
Syncytial Virus ◽  
Epithelial Barrier Dysfunction

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in children worldwide. While most develop a mild, self-limiting illness, some develop severe acute lower respiratory infection and persistent airway disease. Exposure to ambient particulate matter has been linked to asthma, bronchitis, and viral infection in multiple epidemiological studies. We hypothesized that coexposure to nanoparticles worsens RSV-induced airway epithelial barrier dysfunction. Bronchial epithelial cells were incubated with titanium dioxide nanoparticles (TiO2-NP) or a combination of TiO2-NP and RSV. Structure and function of epithelial cell barrier were analyzed. Viral titer and the role of reactive oxygen species (ROS) generation were evaluated. In vivo, mice were intranasally incubated with TiO2-NP, RSV, or a combination. Lungs and bronchoalveolar lavage (BAL) fluid were harvested for analysis of airway inflammation and apical junctional complex (AJC) disruption. RSV-induced AJC disruption was amplified by TiO2-NP. Nanoparticle exposure increased viral infection in epithelial cells. TiO2-NP induced generation of ROS, and pretreatment with antioxidant, N-acetylcysteine, reversed said barrier dysfunction. In vivo, RSV-induced injury and AJC disruption were augmented in the lungs of mice given TiO2-NP. Airway inflammation was exacerbated, as evidenced by increased white blood cell infiltration into the BAL, along with exaggeration of peribronchial inflammation and AJC disruption. These data demonstrate that TiO2-NP exposure exacerbates RSV-induced AJC dysfunction and increases inflammation by mechanisms involving generation of ROS. Further studies are required to determine whether NP exposure plays a role in the health disparities of asthma and other lung diseases, and why some children experience more severe airway disease with RSV infection.

Azithromycin prevents airway epithelial barrier dysfunction induced by sulphur dioxide inhalation

2020 ◽  
Author(s):  
Jennifer Kricker ◽  
Thorarinn Gudjonsson ◽  
Ari Jon Arason ◽  
Jon Pétur Joelsson ◽  
Bryndis Valdimarsdottir ◽  
...  
Keyword(s):  
Sulphur Dioxide ◽  
Epithelial Barrier ◽  
Airway Epithelial ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Dysfunction

scholarly journals Hyaluronan and Layilin Mediate Loss of Airway Epithelial Barrier Function Induced by Cigarette Smoke by Decreasing E-cadherin

2012 ◽  
Vol 287 (50) ◽  
pp. 42288-42298 ◽  
Author(s):  
Rosanna Malbran Forteza ◽  
S. Marina Casalino-Matsuda ◽  
Nieves S. Falcon ◽  
Monica Valencia Gattas ◽  
Maria E. Monzon
Keyword(s):  
Cigarette Smoke ◽  
Barrier Function ◽  
Epithelial Barrier ◽  
Airway Epithelial ◽  
Epithelial Barrier Function ◽  
E Cadherin

Polyamines are required for expression of Toll-like receptor 2 modulating intestinal epithelial barrier integrity

2007 ◽  
Vol 293 (3) ◽  
pp. G568-G576 ◽  
Author(s):  
Jie Chen ◽  
Jaladanki N. Rao ◽  
Tongtong Zou ◽  
Lan Liu ◽  
Bernard S. Marasa ◽  
...  
Keyword(s):  
Barrier Function ◽  
Low Dose ◽  
Epithelial Barrier ◽  
Intestinal Epithelial ◽  
Barrier Dysfunction ◽  
Intestinal Epithelial Barrier ◽  
Tlr2 Expression ◽  
Epithelial Barrier Function ◽  
Cell Functions ◽  
Epithelial Barrier Dysfunction

The Toll-like receptors (TLRs) allow mammalian intestinal epithelium to detect various microbes and activate innate immunity after infection. TLR2 and TLR4 have been identified in intestinal epithelial cells (IECs) as fundamental components of the innate immune response to bacterial pathogens, but the exact mechanism involved in control of TLR expression remains unclear. Polyamines are implicated in a wide variety of biological functions, and regulation of cellular polyamines is a central convergence point for the multiple signaling pathways driving different epithelial cell functions. The current study determined whether polyamines regulate TLR expression, thereby modulating intestinal epithelial barrier function. Depletion of cellular polyamines by inhibiting ornithine decarboxylase (ODC) with α-difluoromethylornithine decreased levels of TLR2 mRNA and protein, whereas increased polyamines by ectopic overexpression of the ODC gene enhanced TLR2 expression. Neither intervention changed basal levels of TLR4. Exposure of normal IECs to low-dose (5 μg/ml) LPS increased ODC enzyme activity and stimulated expression of TLR2 but not TLR4, while polyamine depletion prevented this LPS-induced TLR2 expression. Decreased TLR2 in polyamine-deficient cells was associated with epithelial barrier dysfunction. In contrast, increased TLR2 by the low dose of LPS enhanced epithelial barrier function, which was abolished by inhibition of TLR2 expression with specific, small interfering RNA. These results indicate that polyamines are necessary for TLR2 expression and that polyamine-induced TLR2 activation plays an important role in regulating epithelial barrier function.

scholarly journals Nitric Oxide System and Bronchial Epithelium: More Than a Barrier

2021 ◽  
Vol 12 ◽  
Author(s):  
María Amparo Bayarri ◽  
Javier Milara ◽  
Cristina Estornut ◽  
Julio Cortijo
Keyword(s):  
Nitric Oxide ◽  
Epithelial Cells ◽  
Airway Epithelium ◽  
Lung Diseases ◽  
Bronchial Epithelium ◽  
Bronchial Epithelial Cells ◽  
Epithelial Barrier ◽  
Barrier Dysfunction ◽  
Bronchial Epithelial ◽  
Epithelial Barrier Dysfunction

Airway epithelium forms a physical barrier that protects the lung from the entrance of inhaled allergens, irritants, or microorganisms. This epithelial structure is maintained by tight junctions, adherens junctions and desmosomes that prevent the diffusion of soluble mediators or proteins between apical and basolateral cell surfaces. This apical junctional complex also participates in several signaling pathways involved in gene expression, cell proliferation and cell differentiation. In addition, the airway epithelium can produce chemokines and cytokines that trigger the activation of the immune response. Disruption of this complex by some inflammatory, profibrotic, and carcinogens agents can provoke epithelial barrier dysfunction that not only contributes to an increase of viral and bacterial infection, but also alters the normal function of epithelial cells provoking several lung diseases such as asthma, chronic obstructive pulmonary disease (COPD), cystic fibrosis (CF) or lung cancer, among others. While nitric oxide (NO) molecular pathway has been linked with endothelial function, less is known about the role of the NO system on the bronchial epithelium and airway epithelial cells function in physiological and different pathologic scenarios. Several data indicate that the fraction of exhaled nitric oxide (FENO) is altered in lung diseases such as asthma, COPD, lung fibrosis, and cancer among others, and that reactive oxygen species mediate uncoupling NO to promote the increase of peroxynitrite levels, thus inducing bronchial epithelial barrier dysfunction. Furthermore, iNOS and the intracellular pathway sGC-cGMP-PKG are dysregulated in bronchial epithelial cells from patients with lung inflammation, fibrosis, and malignancies which represents an attractive drug molecular target. In this review we describe in detail current knowledge of the effect of NOS-NO-GC-cGMP-PKG pathway activation and disruption in bronchial epithelial cells barrier integrity and its contribution in different lung diseases, focusing on bronchial epithelial cell permeability, inflammation, transformation, migration, apoptosis/necrosis, and proliferation, as well as the specific NO molecular pathways involved.

scholarly journals Inactivation of the Wnt/β-catenin signaling contributes to the epithelial barrier dysfunction induced by sodium oxalate in canine renal epithelial cells

2021 ◽  
Author(s):  
Yun Ji ◽  
Shuting Fang ◽  
Ying Yang ◽  
Zhenlong Wu
Keyword(s):  
Epithelial Cells ◽  
Barrier Function ◽  
Mdck Cells ◽  
Renal Stones ◽  
Sodium Oxalate ◽  
Epithelial Barrier ◽  
Barrier Dysfunction ◽  
Epithelial Barrier Function ◽  
Epithelial Barrier Dysfunction

Abstract Background Nephrolithiasis (also known as renal stones) is a common disease condition in companion animals, including dogs and cats. Dysfunction of renal tubular epithelial cells involves in the pathogenesis of renal stones. However, a functional role of Wnt/β-catenin signaling and its contribution to nephrolithiasis remains unknown. Results In the present study, we found that Mardin-Darby canine kidney (MDCK) cells treated with sodium oxalate resulted in reduced cell proliferation and migration, which was associated with the G0/G1 phase arrest of cell cycle progression. In addition, sodium oxalate exposure led to decreased transepithelial electrical resistance (TEER) and increased paracellular permeability. The deleterious effect of sodium oxalate on epithelial barrier function was related to decreased protein abundances of claudin-1, occludin, zonula occludens (ZO)-1, ZO-2 and ZO-3. Of note, protein levels of p-β-catenin (Ser552) in MDCK cells were repressed by sodium oxalate, indicating an inhibitory effect on the Wnt/β-catenin signaling. Intriguingly, SB216763, a GSK-3β inhibitor, enhanced the expression p-β-catenin (Ser552), and protected against epithelial barrier dysfunction in sodium oxalate-treated MDCK cells. Conclusion Taken together, our results revealed a critical role of Wnt/β-catenin signaling on the epithelial barrier function of MDCK cells. Activation of Wnt/β-catenin signaling might be an potentially therapeutic target for the treatment of renal stones in animals.

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