[Galectin-7 is associated with bronchial epithelial cell apoptosis in asthmatic children].

OBJECTIVE

It is supposed that bronchial epithelial cells responses to the environmental stimuli are different between asthmatic and non-asthmatic individuals, which contribute to the pathogenesis of asthma. These different responses produce different mediators. If differential gene expressions are found in bronchial epithelial cells of asthmatic and non-asthmatic individuals after the same stimuli in vitro, and these genes are overexpressed in asthmatic children in vivo, then it is concluded that these genes may be associated with asthma. Therefore the authors analyzed the differential gene expressions in the bronchial epithelium cells of asthmatic and non-asthmatic children after RSV infection in vitro. Among these genes, Galectine-7 (lectin, galactoside-binding, soluble, 7, Galectin-7) was 8 times up-regulated in asthmatic children. Galectine-7 was associated with skin keratinocyte apoptosis. The authors hypothesized that Galectin-7 may also be associated with bronchial epithelial cell apoptosis in asthmatic children. The aim of this study was to understand the role of Galectine-7 in bronchial epithelial cell apoptosis in asthma.

METHODS

The bronchial mucosae of one asthmatic child and one non-asthmatic child were obtained by biopsy and cultured in vitro. The bronchial epithelial cells were infected by RSV. The differential gene expressions were analyzed with micro array. Among those differentially expressed genes, Galectin-7 was 8 times up-regulated in asthmatic children. The bronchial mucosae from 10 asthmatic children and 17 non-asthma children were investigated for cell DNA break, Galectine-7 and mRNA expression, Caspase-3 expression by TUNEL, hybridization in situ and immunochemistry. Image analysis was used for quantitative assessment.

RESULTS

Galectine-7 gene was 8 times up-regulated in bronchial epithelial cells from asthmatic children after RSV infection in vitro. Galectin-7 and mRNA were overexpressed in bronchial epithelial cells in asthma in vivo. Bronchial epithelial cell apoptosis increased in asthma in vivo.

CONCLUSION

Galectin-7 may be associated with bronchial epithelial cell apoptosis in asthma.