|
|
||||||||
B1
Department of Pharmacology, University College Dublin, Dublin, Ireland
Glucocorticoids are potent antiinflammatory drugs. They inhibit the
expression of proinflammatory cytokines and adhesion molecules. It has
recently been proposed that the underlying basis to such inhibition is
the induction of the protein I
B, which inhibits the transcription
factor NF-
B. The latter is a key activator of the genes encoding
cytokines and adhesion molecules. The present study shows that the
synthetic glucocorticoid, dexamethasone, inhibits the induction of the
proinflammatory cytokine IL-8 and the adhesion molecules VCAM-1 and
ICAM-1 in human 1321N1 astrocytoma and SK.N.SH neuroblastoma cells.
However, dexamethasone failed to induce I
B or inhibit activation of
NF-
B by IL-1 in the two cell types. EMSA confirmed the identity of
the activated NF-
B by demonstrating that an oligonucleotide,
containing the wild-type NF-
B-binding motif, inhibited formation of
the NF-
B-DNA complexes whereas a mutated form of the NF-
B-binding
motif was ineffective. In addition, supershift analysis showed that the
protein subunits p50 and p65 were prevalent components in the activated
NF-
B complexes. The lack of effect of dexamethasone on the capacity
of IL-1 to activate NF-
B correlated with its inability to induce
I
B and the ability of IL-1 to cause degradation of I
B, even in
the presence of dexamethasone. The results presented in this paper
strongly suggest that glucocorticoids may exert antiinflammatory
effects in cells of neural origin by a mechanism(s) independent of
NF-
B.
This article has been cited by other articles:
![]() |
N. M. Curran, B. D. Griffin, D. O'Toole, K. J. Brady, S. N. Fitzgerald, and P. N. Moynagh The Synthetic Cannabinoid R(+)WIN 55,212-2 Inhibits the Interleukin-1 Signaling Pathway in Human Astrocytes in a Cannabinoid Receptor-independent Manner J. Biol. Chem., October 28, 2005; 280(43): 35797 - 35806. [Abstract] [Full Text] [PDF] |
||||
![]() |
S.-K. Park, W. S. Yang, N. J. Han, S. K. Lee, H. Ahn, I. K. Lee, J. Y. Park, K.-U. Lee, and J. D. Lee Dexamethasone regulates AP-1 to repress TNF-{alpha} induced MCP-1 production in human glomerular endothelial cells Nephrol. Dial. Transplant., February 1, 2004; 19(2): 312 - 319. [Abstract] [Full Text] [PDF] |
||||
![]() |
K. De Bosscher, W. Vanden Berghe, and G. Haegeman The Interplay between the Glucocorticoid Receptor and Nuclear Factor-{kappa}B or Activator Protein-1: Molecular Mechanisms for Gene Repression Endocr. Rev., August 1, 2003; 24(4): 488 - 522. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. Y. Almawi and O. K. Melemedjian Molecular mechanisms of glucocorticoid antiproliferative effects: antagonism of transcription factor activity by glucocorticoid receptor J. Leukoc. Biol., January 1, 2002; 71(1): 9 - 15. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |