Open AccessAnalysis of Lung Gene Expression Reveals a Role for Cl− Channels in Diisocyanate-induced Airway Eosinophilia in a Mouse Model of Asthma Pathology
Author(s) -
Adam V. Wisnewski,
Jian Liu,
Carrie A. Redlich
Publication year - 2020
Publication title -
american journal of respiratory cell and molecular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.469
H-Index - 161
eISSN - 1535-4989
pISSN - 1044-1549
DOI - 10.1165/rcmb.2019-0400oc
Subject(s) - immunology , eosinophilia , chemokine , eosinophil , immunoglobulin e , biology , respiratory tract , gene expression , eotaxin , asthma , respiratory system , inflammation , gene , anatomy , antibody , biochemistry
Diisocyanates are well-recognized causes of asthma. However, sensitized workers frequently lack diisocyanate-specific IgE, which complicates diagnosis and suggests the disease involves IgE-independent mechanisms. We used a mouse model of methylene diphenyl diisocyanate (MDI) asthma to identify biological pathways that may contribute to asthma pathogenesis. MDI sensitization and respiratory tract exposure were performed in Balb/c, transgenic B-cell (e.g., IgE)-deficient mice and a genetic background (C57BL/6)-matched strain. Eosinophils in airway fluid were quantitated by flow cytometry. Lung tissue gene expression was assessed using whole-genome mRNA microarrays. Informatic software was used to identify biological pathways affected by respiratory tract exposure and potential targets for disease intervention. Airway eosinophilia and changes (>1.5-fold; P value < 0.05) in expression of 192 genes occurred in all three mouse strains tested, with enrichment in chemokines and a pattern associated with alternatively activated monocytes/macrophages. CLCA1 (calcium-activated chloride channel regulator 1) was the most upregulated gene transcript (>100-fold) in all exposed mouse lungs versus controls, followed closely by SLC26A4, another transcript involved in Cl - conductance. Crofelemer, a U.S. Food and Drug Administration-approved Cl - channel inhibitor, reduced MDI exposure induction of airway eosinophilia, mucus, CLCA1, and other asthma-associated gene transcripts. Expression changes in a core set of genes occurs independent of IgE in a mouse model of chemical-induced airway eosinophilia. In addition to chemokines and alternatively activated monocytes/macrophages, the data suggest a crucial role for Cl - channels in diisocyanate asthma pathology and as a possible target for intervention.