Objective: To study a possible relationship between expression of the transcription factor glucocorticoid receptor (GR), which mediates antiinflammatory effects, and the transcription factor p50, which mediates proinflammatory effects, in peripheral blood mononuclear cells (PBMC) of patients with rheumatoid arthritis (RA).
Methods: Expression analysis of GR and nuclear factor-kB subunit p50 in PBMC was performed by semiquantitative immunoblotting.
Results: GR and p50 expression in PBMC were significantly increased in patients with RA who had never received corticosteroids. In contrast, GR density is decreased in glucocorticoid treated RA patients. In addition, a dependency between increased GR expression and increased p50 expression was found.
Conclusion: The pathogenesis of RA is not reflected in diminished GR expression but rather in an increased expression level of GR, as well as increased p50 expression in PBMC. Corticosteroids as the major therapeutic drugs result in a reduction of these increased GR and p50 expression levels.