Dysfunctional ErbB2, an EGF receptor family member, hinders repair of airway epithelial cells from asthmatic patients

IntroductionAirway epithelial cells are recognised as an essential controller for the initiation and perpetuation of asthmatic inflammation, yet the detailed mechanisms remain largely unknown. This study aims to investigate the roles and mechanisms of the mechanistic target of rapamycin (MTOR)–autophagy axis in airway epithelial injury in asthma.MethodsWe examined the MTOR–autophagy signalling in airway epithelium from asthmatic patients or allergic mice induced by ovalbumin or house dust mites, or in human bronchial epithelial (HBE) cells. Furthermore, mice with specific MTOR knockdown in airway epithelium and autophagy-related lc3b-/- mice were used for allergic models.ResultsMTOR activity was decreased, while autophagy was elevated, in airway epithelium from asthmatic patients or allergic mice, or in HBE cells treated with IL33 or IL13. These changes were associated with upstream tuberous sclerosis protein 2 signalling. Specific MTOR knockdown in mouse bronchial epithelium augmented, while LC3B deletion diminished allergen-induced airway inflammation and mucus hyperproduction. The worsened inflammation caused by MTOR deficiency was also ameliorated in lc3b-/- mice. Mechanistically, autophagy was induced later than the emergence of allergen-initiated inflammation, particularly IL33 expression. MTOR deficiency increased, while knocking out of LC3B abolished the production of IL25 and the eventual airway inflammation on allergen challenge. Blocking IL25 markedly attenuated the exacerbated airway inflammation in MTOR-deficiency mice.ConclusionCollectively, these results demonstrate that allergen-initiated inflammation suppresses MTOR and induces autophagy in airway epithelial cells, which results in the production of certain proallergic cytokines such as IL25, further promoting the type 2 response and eventually perpetuating airway inflammation in asthma.

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Neutrophils from severe asthmatic patients induce epithelial to mesenchymal transition in healthy bronchial epithelial cells

Respiratory Research ◽

10.1186/s12931-019-1186-8 ◽

2019 ◽

Vol 20 (1) ◽

Cited By ~ 3

Author(s):

Alexandre Haddad ◽

Mellissa Gaudet ◽

Maria Plesa ◽

Zoulfia Allakhverdi ◽

Andrea K. Mogas ◽

...

Keyword(s):

Epithelial Cells ◽

Epithelial To Mesenchymal Transition ◽

Airway Remodeling ◽

Airway Epithelial Cells ◽

Airway Epithelial ◽

Bronchial Epithelial ◽

Mesenchymal Transition ◽

Asthmatic Patients ◽

Severe Asthmatic ◽

Tgf Β1

Abstract Background Asthma is a heterogenous disease characterized by chronic inflammation and airway remodeling. An increase in the severity of airway remodeling is associated with a more severe form of asthma. There is increasing interest in the epithelial to mesenchymal transition process and mechanisms involved in the differentiation and repair of the airway epithelium, especially as they apply to severe asthma. Growing evidence suggests that Epithelial-Mesenchymal transition (EMT) could contribute to airway remodeling and fibrosis in asthma. Severe asthmatic patients with remodeled airways have a neutrophil driven inflammation. Neutrophils are an important source of TGF-β1, which plays a role in recruitment and activation of inflammatory cells, extracellular matrix (ECM) production and fibrosis development, and is a potent inducer of EMT. Objective As there is little data examining the contribution of neutrophils and/or their mediators to the induction of EMT in airway epithelial cells, the objective of this study was to better understand the potential role of neutrophils in severe asthma in regards to EMT. Methods We used an in vitro system to investigate the neutrophil-epithelial cell interaction. We obtained peripheral blood neutrophils from severe asthmatic patients and control subjects and examined for their ability to induce EMT in primary airway epithelial cells. Results Our data indicate that neutrophils from severe asthmatic patients induce changes in morphology and EMT marker expression in bronchial epithelial cells consistent with the EMT process when co-cultured. TGF-β1 levels in the culture medium of severe asthmatic patients were increased compared to that from co-cultures of non-asthmatic neutrophils and epithelial cells. Conclusions and clinical relevance As an inducer of EMT and an important source of TGF-β1, neutrophils may play a significant role in the development of airway remodeling and fibrosis in severe asthmatic airways.

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MicroRNA-145-5p promotes asthma pathogenesis by inhibiting kinesin family member 3A expression in mouse airway epithelial cells

Journal of International Medical Research ◽

10.1177/0300060518789819 ◽

2019 ◽

Vol 47 (7) ◽

pp. 3307-3319 ◽

Cited By ~ 2

Author(s):

Tao Xiong ◽

Ying Du ◽

Zhou Fu ◽

Gang Geng

Keyword(s):

Epithelial Cells ◽

Family Member ◽

Airway Epithelial Cells ◽

Epithelial Barrier ◽

Airway Epithelial ◽

Cytokine Release ◽

Barrier Dysfunction ◽

Epithelial Repair ◽

Epithelial Barrier Dysfunction ◽

Kinesin Family

Background MicroRNA (miR)-145-5p is a respiratory disease biomarker, and is upregulated in asthma pathogenesis. However, its underlying mechanisms were unclear, so were investigated in the present study. Methods A mouse model of asthma was established by challenge with house dust mite (HDM) extract. An miR-145-5p antagomir was administered nasally and expression of kinesin family member 3A (KIF3A) and miR-145-5p was measured by immunohistochemistry, PCR, and western blot. Eosinophils in lavage fluid and levels of interleukin (IL)-4, IL-5, and IL-13 were quantified. Airway hyper-responsiveness was measured and KIF3A expression was tested following miR-145-5p overexpression or interference in the 16HBE14o- airway epithelial cell line. The effects of miR-145-5p and KIF3A co-transfection in 16HBE14o- cells were examined on cytokine release, epithelial barrier dysfunction, and epithelial repair in HDM-exposed cells. Results KIF3A downregulation and miR-145-5p upregulation were noted in airway epithelial cells of HDM-exposed asthmatic mice, while miR-145-5p antagonism significantly improved symptoms. MiR-145-5p promoted the HDM-induced release of chemokines and inflammatory factors and epithelial barrier dysfunction, and suppressed epithelial repair by directly targeting KIF3A. Conclusion miR-145-5p influenced HDM-induced epithelial cytokine release and epithelial barrier dysfunction via regulating KIF3 expression. It also affected epithelial repair, exacerbating the HDM-induced T helper 2-type immune response in mice.

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Activation of the EGF receptor signaling pathway in airway epithelial cells exposed to Utah Valley PM

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.2001.281.2.l483 ◽

2001 ◽

Vol 281 (2) ◽

pp. L483-L489 ◽

Cited By ~ 44

Author(s):

Weidong Wu ◽

James M. Samet ◽

Andrew J. Ghio ◽

Robert B. Devlin

Keyword(s):

Epithelial Cells ◽

Intracellular Signaling ◽

Egf Receptor ◽

Kinase Inhibitor ◽

Airway Epithelial Cells ◽

Mitogen Activated Protein Kinase ◽

Receptor Signaling ◽

Airway Epithelial ◽

Steel Mill ◽

Adverse Health Effects

Exposure to ambient particulate matter (PM) in the Utah Valley has previously been associated with a variety of adverse health effects. To investigate intracellular signaling mechanisms for pulmonary responses to Utah Valley PM inhalation, human primary airway epithelial cells were exposed to aqueous extracts of PM collected from the year before (Y1), during (Y2), and after (Y3) the closure of a local steel mill located in the Utah Valley in this study. Transfection with kinase-deficient extracellular signal-regulated kinase (ERK) 1 constructs partially blocked Utah Valley PM-induced interleukin (IL)-8 promoter reporter activity. The mitogen-activated protein kinase/ERK kinase (MEK) activity inhibitor PD-98059 significantly abolished IL-8 released in response to Utah Valley PM, as did the epidermal growth factor (EGF) receptor kinase inhibitor AG-1478. Western blotting showed that Utah Valley PM induced phosphorylation of EGF receptor tyrosine, MEK1/2, and ERK1/2, which could be ablated with AG-1478 or PD-98059. For all findings, the potency of Utah Valley PM collected during Y2 was found to be lower relative to that of Y1 and Y3. These data demonstrate that Utah Valley PM can induce IL-8 expression partially through the activation of the EGF receptor signaling.

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