scholarly journals Brg1 Promotes Airway Mucus Hypersecretion via IL-13 and the JAK1/2-STAT6 Signaling Pathway in Asthma

Author(s):  
Wenjing Zou ◽  
maozhu xu ◽  
Jie Hu ◽  
Lili Yang ◽  
Gang Gen ◽  
...  

Abstract Backgroud: The chromatin remodeling factor Brg1 (Brahma-related gene 1) is an important nuclear protein that promotes the transcriptional activation or inhibition of target genes by regulating ATP hydrolysis to generate energy which rearranges the position of nucleosomes and the interaction of histone DNA. In this study, we explored the effect of Brg1 on airway mucus hypersecretion in asthma.Methods: Six-to-eight-week-old female wild-type C57BL/6 mice (wild-type, WT) and type II alveolar epithelial cells (AECIIs) specifically knockout Brg1 mice (Brg1fl/fl) were selected as the experimental subjects. The asthma group was established with house dust mite (HDM), and the control group was treated with normal saline (n=10). Wright's staining was used to detect inflammatory cells in bronchoalveolar lavage fluid (BALF). Invasive lung function was used to assess the airway compliance. Hematoxylin and eosin and periodic acid-schiff staining were used to detect mucus secretion. The virus was used to knock down the Brg1 gene in the bronchial epithelial cell line (16HBE) and stimulated with HDM. Immunohistochemistry was used to measure mucin glycoprotein 5AC (MUC5AC) protein expression in the airway epithelium and 16HBE cells. Western blotting was used to detect the expression of the MUC5AC and JAK1/2-STAT6 signaling pathways in mouse lung tissue and 16HBE. Co-immunoprecipitation (Co-IP) and Chromatin Immunoprecipitation (CHIP) were used to detect whether Brg1 could regulate the JAK1/2-STAT6 signaling pathway.Results: Specifically, knocking out the Brg1 gene in AECIIs can reduce airway inflammation, airway compliance, and mucus hypersecretion in asthma. Knockdown of the Brg1 gene can simultaneously reduce Interleukin-13 (IL-13) and the expression of MUC5AC protein in airway epithelial cells and the activation of the JAK1/2-STAT6 signaling pathway. The results of Co-IP and CHIP showed that Brg1 could bind to the JAK1/2 promoter region, regulating the activity of the JAK1/2-STAT6 pathway affects airway mucus secretion in asthma.Conclusion: Brg1 gene knockout in airway epithelial cells can reduce asthmatic airway mucus hypersecretion and the expression of MUC5AC protein in airway epithelial cells partly by inhibiting the activation of the JAK1/2-STAT6 signaling pathway.

2011 ◽  
Vol 25 (2) ◽  
pp. 69-74 ◽  
Author(s):  
Takao Ogawa ◽  
Shino Shimizu ◽  
Ichiro Tojima ◽  
Hideaki Kouzaki ◽  
Takeshi Shimizu

2019 ◽  
Vol 8 (5) ◽  
pp. 704-710
Author(s):  
Soyoung Kwak ◽  
Yoon Seok Choi ◽  
Hyung Gyun Na ◽  
Chang Hoon Bae ◽  
Si-Youn Song ◽  
...  

Abstract Mucus plays an important role in protecting the respiratory tract from irritants. However, mucus hypersecretion is a major indicator of airway diseases. 1,2-Benzisothiazolin-3-one (BIT), as a microbicide, induces asthmatic inflammation. Therefore, we focused on the effects of BIT-related mucin secretion in airway epithelial cells. Our in vivo study showed increased mucus and MUC5AC expressions in the bronchioles of mice that inhaled BIT. For investigating the signaling pathways, we performed experiments in human airway epithelial cells. BIT induced the MUC5AC expression and significantly increased the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), p38, and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). The specific inhibitors of ERK1/2, p38, and NF-κB blocked the BIT-induced MUC5AC expression. Therefore, these results suggest that BIT induces the MUC5AC expression via the ERK1/2, p38, and NF-κB pathways in human airway epithelial cells, which may be involved in mucus hypersecretion associated with airway inflammatory diseases.


2006 ◽  
Vol 347 (4) ◽  
pp. 852-858 ◽  
Author(s):  
Daisuke Inoue ◽  
Muneo Numasaki ◽  
Mika Watanabe ◽  
Hiroshi Kubo ◽  
Takahiko Sasaki ◽  
...  

2008 ◽  
Vol 76 (12) ◽  
pp. 5447-5455 ◽  
Author(s):  
S. Umadevi Sajjan ◽  
Lisa A. Carmody ◽  
Carlos F. Gonzalez ◽  
John J. LiPuma

ABSTRACT Burkholderia cenocepacia is an important respiratory pathogen in persons with cystic fibrosis (CF). Recent studies indicate that B. cenocepacia survives within macrophages and airway epithelial cells in vitro by evading endosome-lysosome fusion. We investigated the role of a plasmid-encoded type IV secretion system in the intracellular survival, replication, and processing of B. cenocepacia. Both a wild-type strain (K56-2) and its type IV secretion system mutant (designated LC101) entered and replicated in CF airway epithelial cells and monocyte-derived macrophages. However, significantly more intracellular K56-2 than LC101 bacteria were found in both cell types at 24 h postinfection. Colocalization of bacteria with markers of the classical endocytic pathway indicated that although both K56-2 and LC101 reside transiently in early endosomes, a greater proportion of the mutant bacteria are targeted to lysosomal degradation. In contrast, wild-type bacteria escape from the classical endocytic pathway and traffic to the endoplasmic reticulum, where they replicate. Our results show that the intracellular processing of B. cenocepacia is similar in both professional and nonprofessional phagocytes and that a functional plasmid-encoded type IV secretion system contributes to the survival and replication of B. cenocepacia in eukaryotic cells.


2012 ◽  
Vol 303 (2) ◽  
pp. L97-L106 ◽  
Author(s):  
Shilpa Nimishakavi ◽  
Marina Besprozvannaya ◽  
Wilfred W. Raymond ◽  
Charles S. Craik ◽  
Dieter C. Gruenert ◽  
...  

Prostasin is a membrane-anchored protease expressed in airway epithelium, where it stimulates salt and water uptake by cleaving the epithelial Na+ channel (ENaC). Prostasin is activated by another transmembrane tryptic protease, matriptase. Because ENaC-mediated dehydration contributes to cystic fibrosis (CF), prostasin and matriptase are potential therapeutic targets, but their catalytic competence on airway epithelial surfaces has been unclear. Seeking tools for exploring sites and modulation of activity, we used recombinant prostasin and matriptase to identify substrate t-butyloxycarbonyl-l-Gln-Ala-Arg-4-nitroanilide (QAR-4NA), which allowed direct assay of proteases in living cells. Comparisons of bronchial epithelial cells (CFBE41o−) with and without functioning cystic fibrosis transmembrane conductance regulator (CFTR) revealed similar levels of apical and basolateral aprotinin-inhibitable activity. Although recombinant matriptase was more active than prostasin in hydrolyzing QAR-4NA, cell surface activity resisted matriptase-selective inhibition, suggesting that prostasin dominates. Surface biotinylation revealed similar expression of matriptase and prostasin in epithelial cells expressing wild-type vs. ΔF508-mutated CFTR. However, the ratio of mature to inactive proprostasin suggested surface enrichment of active enzyme. Although small amounts of matriptase and prostasin were shed spontaneously, prostasin anchored to the cell surface by glycosylphosphatidylinositol was the major contributor to observed QAR-4NA-hydrolyzing activity. For example, the apical surface of wild-type CFBE41o− epithelial cells express 22% of total, extractable, aprotinin-inhibitable, QAR-4NA-hydrolyzing activity and 16% of prostasin immunoreactivity. In conclusion, prostasin is present, mature and active on the apical surface of wild-type and CF bronchial epithelial cells, where it can be targeted for inhibition via the airway lumen.


2004 ◽  
Vol 286 (4) ◽  
pp. L650-L657 ◽  
Author(s):  
Yingjian You ◽  
Tao Huang ◽  
Edward J. Richer ◽  
Jens-Erik Harboe Schmidt ◽  
Joseph Zabner ◽  
...  

Factors required for commitment of an undifferentiated airway epithelial cell to a ciliated cell are unknown. Cell ultrastructure analysis indicates ciliated cell commitment activates a multistage program involving synthesis of cilia precursor proteins and assembly of macromolecular complexes. Foxj1 is an f-box transcription factor expressed in ciliated cells and shown to be required for cilia formation by gene deletion in a mouse model. To identify a specific role for foxj1 in directing the ciliated cell phenotype, we evaluated the capacity of foxj1 to induce ciliogenesis and direct cilia assembly. In a primary culture model of wild-type mouse airway epithelial cells, foxj1 expression preceded the appearance of cilia and in cultured foxj1 null cells cilia did not develop. Delivery of foxj1 to polarized epithelial cell lines and primary cultured alveolar epithelial cells failed to promote ciliogenesis. Similarly, delivery of foxj1 to wild-type airway epithelial cells did not enhance the total number of ciliated cells. In contrast, delivery of foxj1 to null cells resulted in the appearance of cilia. Analysis revealed that, in the absence of foxj1, null cells contained cilia precursor basal bodies, indicating prior commitment to ciliogenesis. However, the basal bodies were disorganized within the apical compartment and failed to dock with the apical membrane. Reconstitution of foxj1 in null cells restored normal basal body organization, resulting in axoneme growth. Thus foxj1 functions in late-stage ciliogenesis to regulate programs promoting basal body docking and axoneme formation in cells previously committed to the ciliated cell phenotype.


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