Macrophage migration inhibitory factor (MIF) is an inflammatory cytokine secreted by several cell types, including mononuclear and pituitary cells. It has also been shown to counteract cortisol-induced inhibition of inflammatory cytokine secrauton. The purpose of this study was to determine whether MIF antagonized the effect of hydrocortisone on the NF-κB/IκB signal transduction pathway in lipopolysaccharide (LPS)-stimulated human peripheral blood mononuclear cells. Physiological doses of hydrocortisone (50-200 ng/ml) diminished both the LPS-stimulated decrease in cytosolic IκBα levels and the subsequent increase in nuclear NF-κB DNA binding. In the presence of both LPS and hydrocortisone, 1 ng/ml of MIF antagonized the effects of hydrocortisone, resulting in decreased cytosolic IκBα levels (P < 0.05) and increased nuclear NF-κB DNA binding (P < 0.05). In the absence of hydrocortisone, MIF had no effect on LPS-induced decreases in IκBα. In the absence of LPS, MIF inhibited hydrocortisone-induced increases in IκBα (P = 0.03). Thus the mechanism by which MIF antagonizes the effect of hydrocortisone on the NF-kB/IκB signal transduction pathway is through inhibiting the ability of hydrocortisone to increase cytosolic IκBα.
|Original language||English (US)|
|Journal||American Journal of Physiology - Regulatory Integrative and Comparative Physiology|
|Issue number||3 48-3|
|State||Published - Oct 3 2000|
ASJC Scopus subject areas
- Physiology (medical)