Nasal epithelial barrier disruption by particulate matter ≤2.5 μm via tight junction protein degradation

Abstract Background: While exposure to diesel exhaust particles has been linked to aberrant immune responses in allergic diseases such as asthma, little attention has been paid to their effects on the airway epithelium. In this study, we sought to determine the effect of diesel exhaust exposure on airway epithelial barrier function and composition using in vitro and in vivo model systems. Methods: 16HBE14o- human bronchial epithelial cells were grown on collagen coated Transwell inserts and exposed to 5 to 50 µg/cm2 SRM 2975 diesel particulate matter (DEP) suspended in cell culture medium or vehicle controls. Changes in barrier function were assessed by measuring transepithelial electrical resistance (TEER) and permeability to 4 kDa FITC Dextran. Neonatal BALB/c mice were exposed to aerosolized DEP (255 ± 89 µg/m3; 2 hours per day for 5 days) and changes in the tight junction protein Tricellulin were assessed two weeks post exposure. Results: A six-hour incubation of epithelial cells with diesel exhaust particles caused a significant concentration-dependent reduction in epithelial barrier integrity as measured by decreased TEER and increased permeability to 4 kDa FITC-Dextran. This reduction in epithelial barrier integrity corresponded to a significant reduction in expression of the tight junction protein Tricellulin. siRNA mediated knockdown of Tricellulin recapitulated changes in barrier function caused by DEP exposure. Neonatal exposure to aerosolized DEP caused a significant reduction in lung Tricellulin two weeks post exposure at both the protein and mRNA level. Conclusion: Short term exposure to DEP causes a significant reduction in epithelial barrier integrity through a reduction in the tight junction protein Tricellulin. Neonatal exposure to aerosolized DEP caused a significant and sustained reduction in Tricellulin protein and mRNA in the lung, suggesting that early life exposure to inhaled DEP may cause lasting changes in airway epithelial barrier function.

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Diesel Exhaust Particle Exposure Reduces Expression of the Epithelial Tight Junction Protein Tricellulin

10.21203/rs.3.rs-25522/v1 ◽

2020 ◽

Author(s):

Timothy Smyth ◽

Janelle Veazey ◽

Sophia Eliseeva ◽

David Chalupa ◽

Alison Elder ◽

...

Keyword(s):

Tight Junction ◽

Diesel Exhaust ◽

Barrier Function ◽

Diesel Exhaust Particles ◽

Tight Junction Protein ◽

Epithelial Barrier ◽

Airway Epithelial ◽

Epithelial Barrier Function ◽

Barrier Integrity ◽

Junction Protein

Abstract Background While exposure to diesel exhaust particles has been linked to aberrant immune responses in allergic diseases such as asthma, little attention has been payed to their effects on the airway epithelium. In this study, we sought to determine the effect of diesel exhaust exposure on airway epithelial barrier function and composition using in vitro and in vivo model systems. 16HBE14o- human bronchial epithelial cells were grown on collagen coated Transwell inserts and exposed to 5 to 50 µg/cm2 SRM 2975 diesel particulate matter (DEP) suspended in cell culture medium or vehicle controls. Changes in barrier function were assessed by measuring transepithelial electrical resistance (TEER) and permeability to 4 kDa FITC Dextran. Neonatal BALB/c mice were exposed to aerosolized DEP (255 ± 89 µg/m3; 2 hours per day for 5 days) and changes in the tight junction protein Tricellulin were assessed two weeks post exposure. Results A six-hour incubation of epithelial cells with diesel exhaust particles caused a significant concentration-dependent reduction in epithelial barrier integrity as measured by decreased TEER and increased permeability to 4 kDa FITC-Dextran. This reduction in epithelial barrier integrity corresponded to a significant reduction in expression of the tight junction protein Tricellulin. siRNA mediated knockdown of Tricellulin recapitulated changes in barrier function caused by DEP exposure. Neonatal exposure to aerosolized DEP caused a significant reduction in lung Tricellulin two weeks post exposure at both the protein and mRNA level. Conclusion Short term exposure to DEP causes a significant reduction in epithelial barrier integrity through a reduction in the tight junction protein Tricellulin. Neonatal exposure to aerosolized DEP caused a significant and sustained reduction in Tricellulin protein and mRNA in the lung, suggesting that early life exposure to inhaled DEP may cause lasting changes in airway epithelial barrier function.

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Diesel exhaust particle exposure reduces expression of the epithelial tight junction protein Tricellulin

Particle and Fibre Toxicology ◽

10.1186/s12989-020-00383-x ◽

2020 ◽

Vol 17 (1) ◽

Author(s):

Timothy Smyth ◽

Janelle Veazey ◽

Sophia Eliseeva ◽

David Chalupa ◽

Alison Elder ◽

...

Keyword(s):

Tight Junction ◽

Diesel Exhaust ◽

Barrier Function ◽

Diesel Exhaust Particles ◽

Tight Junction Protein ◽

Epithelial Barrier ◽

Airway Epithelial ◽

Epithelial Barrier Function ◽

Barrier Integrity ◽

Junction Protein

Abstract Background While exposure to diesel exhaust particles has been linked to aberrant immune responses in allergic diseases such as asthma, little attention has been paid to their effects on the airway epithelial barrier. In this study, we sought to determine the effect of diesel exhaust exposure on airway epithelial barrier function and composition using in vitro and in vivo model systems. Methods 16HBE14o- human bronchial epithelial cells were grown on collagen coated Transwell inserts and exposed to 5 to 50 μg/cm2 SRM 2975 diesel particulate matter (DEP) suspended in cell culture medium or vehicle controls. Changes in barrier function were assessed by measuring transepithelial electrical resistance (TEER) and permeability to 4 kDa FITC Dextran. Neonatal BALB/c mice were exposed to aerosolized DEP (255 ± 89 μg/m3; 2 h per day for 5 days) and changes in the tight junction protein Tricellulin were assessed 2 weeks post exposure. Results A six-hour incubation of epithelial cells with diesel exhaust particles caused a significant concentration-dependent reduction in epithelial barrier integrity as measured by decreased TEER and increased permeability to 4 kDa FITC-Dextran. This reduction in epithelial barrier integrity corresponded to a significant reduction in expression of the tight junction protein Tricellulin. siRNA mediated knockdown of Tricellulin recapitulated changes in barrier function caused by DEP exposure. Neonatal exposure to aerosolized DEP caused a significant reduction in lung Tricellulin 2 weeks post exposure at both the protein and mRNA level. Conclusion Short term exposure to DEP causes a significant reduction in epithelial barrier integrity through a reduction in the tight junction protein Tricellulin. Neonatal exposure to aerosolized DEP caused a significant and sustained reduction in Tricellulin protein and mRNA in the lung, suggesting that early life exposure to inhaled DEP may cause lasting changes in airway epithelial barrier function.

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Sa1439 Soluble Protein P40 Produced by Lactobacillus rhamnosus GG Enhances Tight Junction Protein Expression and Prevents IFN Gamma-Induced Epithelial Barrier Damage in Human Enteroids

Gastroenterology ◽

10.1016/s0016-5085(16)31108-8 ◽

2016 ◽

Vol 150 (4) ◽

pp. S316

Author(s):

Xu Han ◽

Ji-Yao Li ◽

Sha Huang ◽

Jason Spence ◽

Chung Owyang

Keyword(s):

Protein Expression ◽

Tight Junction ◽

Soluble Protein ◽

Lactobacillus Rhamnosus ◽

Tight Junction Protein ◽

Epithelial Barrier ◽

Lactobacillus Rhamnosus Gg ◽

Ifn Gamma ◽

Tight Junction Protein Expression ◽

Junction Protein

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Tricellular Tight Junction Protein Tricellulin Is Targeted by the Enteropathogenic Escherichia coli Effector EspG1, Leading to Epithelial Barrier Disruption

Infection and Immunity ◽

10.1128/iai.00700-16 ◽

2016 ◽

Vol 85 (1) ◽

Cited By ~ 6

Author(s):

Vijay Morampudi ◽

Franziska A. Graef ◽

Martin Stahl ◽

Udit Dalwadi ◽

Victoria S. Conlin ◽

...

Keyword(s):

Escherichia Coli ◽

Tight Junction ◽

Significant Loss ◽

Effector Proteins ◽

Epithelial Barrier ◽

Tight Junction Proteins ◽

Barrier Dysfunction ◽

Barrier Disruption ◽

Junction Protein ◽

Junction Proteins

ABSTRACT Enteropathogenic Escherichia coli (EPEC)-induced diarrhea is often associated with disruption of intestinal epithelial tight junctions. Although studies have shown alterations in the expression and localization of bicellular tight junction proteins during EPEC infections, little is known about whether tricellular tight junction proteins (tTJs) are affected. Using Caco-2 cell monolayers, we investigated if EPEC is capable of targeting the tTJ protein tricellulin. Our results demonstrated that at 4 h postinfection, EPEC induced a significant reduction in tricellulin levels, accompanied by a significant loss of transepithelial resistance (TEER) and a corresponding increase in paracellular permeability. Conversely, cells overexpressing tricellulin were highly resistant to EPEC-induced barrier disruption. Confocal microscopy revealed the distribution of tricellulin into the plasma membrane of infected epithelial cells and confirmed the localization of EPEC aggregates in close proximity to tTJs. Moreover, infections with EPEC strains lacking genes encoding specific type III secreted effector proteins demonstrated a crucial role for the effector EspG1 in modulating tricellulin expression. Complementation studies suggest that the EspG-induced depletion of tricellulin is microtubule dependent. Overall, our results show that EPEC-induced epithelial barrier dysfunction is mediated in part by EspG1-induced microtubule-dependent depletion of tricellulin.

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