FcepsilonRI-mediated amphiregulin production by human mast cells increases mucin gene expression in epithelial cells.
BACKGROUND
Topical application of a glucocorticoid is now widely recognized as the first-line therapy for bronchial asthma. However, glucocorticoid treatment is largely ineffective in relation to overproduction of sputum and lung tissue remodeling.


OBJECTIVE
The purpose of the current study was to identify human mast cell (MC) products that are related to goblet cell hyperplasia.


METHODS
The FcepsilonRI-mediated gene expression profile of MCs was examined by using high-density oligonucleotide probe arrays and RT-PCR. Secretion of a protein, amphiregulin, by the MCs was measured by ELISA. Upregulation of mucin genes in NCI-H292 cells by amphiregulin was evaluated by real-time RT-PCR. The expression levels of amphiregulin on histological sections obtained from 40 subjects with asthma and 6 healthy control subjects were estimated by immunohistochemical staining, and the correlation with the number of goblet cells was studied.


RESULTS
Amphiregulin was secreted by human MCs after aggregation of FcepsilonRI, and its expression was not inhibited by a glucocorticoid (dexamethasone). Amphiregulin upregulated mucin gene expression in airway epithelial cells. Upregulation of amphiregulin expression was observed in MCs of patients with asthma, but not normal control subjects. Furthermore, upregulation of amphiregulin in MCs significantly correlated with the extent of goblet cell hyperplasia in the mucosa of patients with bronchial asthma.


CONCLUSIONS
These results suggest that after exposure to antigens, human MCs may induce sputum production via release of amphiregulin. Therefore, amphiregulin may be a new target molecule for treatment of overproduction of sputum in bronchial asthma.
Okumura
Shigeru
S
Research Center for Allergy and Immunology, RIKEN Yokohama Institute, Yokohama, Japan.
Sagara
Hironori
H
Fukuda
Takeshi
T
Saito
Hirohisa
H
Okayama
Yoshimichi
Y
D066258:Amphiregulin; D001249:Asthma / Q000378:metabolism* / Q000473:pathology; D001980:Bronchi / Q000378:metabolism* / Q000473:pathology; D016022:Case-Control Studies; D003907:Dexamethasone / Q000494:pharmacology; D066255:EGF Family of Proteins; D015870:Gene Expression / Q000187:drug effects; D005938:Glucocorticoids / Q000494:pharmacology; D006023:Glycoproteins / Q000096:biosynthesis* / Q000494:pharmacology; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000096:biosynthesis* / Q000494:pharmacology; D008407:Mast Cells / Q000378:metabolism*; D055271:Mucin 5AC; D055262:Mucin-2; D009077:Mucins / Q000235:genetics / Q000378:metabolism*; D017455:Receptors, IgE / Q000378:metabolism*; D020545:Respiratory Mucosa / Q000378:metabolism* / Q000473:pathology; D015854:Up-Regulation
C587848:AREG protein, human; D066258:Amphiregulin; D066255:EGF Family of Proteins; D005938:Glucocorticoids; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; C524625:MUC2 protein, human; C524678:MUC5AC protein, human; D055271:Mucin 5AC; D055262:Mucin-2; D009077:Mucins; D017455:Receptors, IgE; D003907:Dexamethasone