Korean J Asthma Allergy Clin Immunol.  2008 Sep;28(3):220-225.

Effects of GR beta Overexpression on Steroid-induced Changes of the Whole Genes in the A549 Airway Epithelial Cells

Abstract

BACKGROUND: Glucocorticoid receptor beta (GR beta) may not bind to ligands and is thought to affect gene transcription only by acting as a dominant negative inhibitor of Glucocorticoid receptor alpha (GR alpha). However, there have been few reports about the functional roles of GR beta in the steroid-induces changes of gene expression.
OBJECTIVE
To investigate the functional role of GR beta overexpression in the steroid- induced changes of gene expression. METHOD: The changes in gene expressions such as steroid- induced synthesis of genes, TNF-alpha-induced synthesis of inflammatory genes and steroid induced suppression of activated genes by TNF-alpha treatment were compared with and without pCMV GR beta expression. RESULT: The number of genes increased by dexamethasone treatment only in the GR beta transfected group were 54. Increased expressions of genes by dexamethasone treatment were not affected by GR beta overexpression. The number of genes increased by TNF-alpha treatment only in the GR beta-transfected group were 69. Expressions of genes increased by TNF-alpha treatment in both the control and the GR beta-transfected group were decreased by further dexamethasone treatment in a similar manner.
CONCLUSION
The results of this study suggest that GR beta may not be a dominant negative inhibitor in the steroid- induced changes of genes and that it may have some functional roles in the regulation of gene expressions.

MeSH Terms

Dexamethasone
Epithelial Cells
Gene Expression
Ligands
Receptors, Glucocorticoid
Tumor Necrosis Factor-alpha
Dexamethasone
Ligands
Receptors, Glucocorticoid
Tumor Necrosis Factor-alpha