Am. J. Respir. Cell Mol. Biol., Vol 17, No. 1, 07 1997, 106-113.
Identification of novel inducible genes in airway epithelium
LM Schwiebert, JL Mooney, S Van Horn, A Gupta and RP Schleimer
Department of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.
DNA differential display analysis (DD-PCR) was utilized to identify genes
that are expressed in airway epithelium and are relevant to airway
inflammation; cytokine-mediated induction of gene expression and inhibition
of that induction by glucocorticoids were the criteria for selection. The
IB3-1 cell line was cultured in the presence of tumor necrosis factor-alpha
(TNF-alpha), dexamethasone, or dimethyl sulfoxide (DMSO) as a control, and
analyzed via DD-PCR and Northern blot analyses. With this approach, two
TNF-alpha-inducible and dexamethasone (DEX)-sensitive expressed sequence
tags (EST8 and EST19) were identified. In IB3-1 cells, TNF-alpha increased
messenger RNA (mRNA) expression of EST8 (34%, P < or = 0.005) and EST19
(41%, P < or = 0.01), whereas dexamethasone reduced this expression to
resting levels. This pattern of mRNA expression was also observed in normal
human bronchial epithelial cells (EST8: 21%, P < or = 0.009; EST19: 11%,
P < or = 0.02) and in the basophil leukemia cell line KU812 (EST8: 34%,
P < or = 0.01). Through basic local alignment search tool (BLAST)
analysis, it was determined that these ESTs exhibited significant homology
with the monomeric G protein rhoC (EST8: 100% homology, P = 1.6 x 10(-100))
and the UFO tyrosine kinase receptor (EST19: 86% homology, 5.3 x 10(- 28).
