Abstract
Interleukin (IL-1) and tumor necrosis factor (TNF) activate human lung fibroblasts through interactions with specific receptors. One effect of this interaction of IL-1 and TNF with fibroblasts is an increased production of the cytokines, IL-6 and IL-8. Dexamethasone blocks the induction of IL-6 and IL-8 by IL-1 or TNF. In these studies, we determined whether dexamethasone interferes with the upregulation of IL-6 and IL-8 by downregulating expression of the IL-1 or TNF receptor genes. Confluent lung fibroblasts were treated with medium alone (control) or medium with dexamethasone (10-6 M). Dexamethasone did not decrease the binding of IL-1 and TNF to their receptors, nor did it decrease amounts of IL-1 or TNF receptor RNA. Both IL- 1 and TNF increased release of IL-6 and IL-8 from the cells in a dose- dependent manner and dexamethasone inhibited this effect. Dexamethasone also inhibited the induction of IL-6 and IL-8 RNA by IL-1 and TNF. The studies show that dexamethasone does not block the effects of IL-1 or NTF on fibroblasts by decreasing expression of IL-1 or TNF receptors.
Original language | English (US) |
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Pages (from-to) | L33-L38 |
Journal | American Journal of Physiology - Lung Cellular and Molecular Physiology |
Volume | 267 |
Issue number | 1 11-1 |
DOIs | |
State | Published - 1994 |
Keywords
- corticosteroid
- cytokine
- fibrosis
ASJC Scopus subject areas
- Physiology
- Pulmonary and Respiratory Medicine
- Physiology (medical)
- Cell Biology