title: Increased IkappaB expression and diminished nuclear NF-kappaB in human mononuclear cells following hydrocortisone injection.
abstract: We have recently demonstrated that hydrocortisone and other glucocorticoids inhibit reactive oxygen species (ROS) generation by mononuclear (MNC) and polymorphonuclear leucocytes (PMNL). Since NF-kappaB/IkappaB system regulates the transcription of proinflammatory genes, including those responsible for ROS generation, we tested the hypothesis that hydrocortisone may stimulate IkappaB production thus inhibiting NF-kappaB translocation from the cytosol into the nucleus in MNC, in vivo. One hundred milligram of hydrocortisone was injected intravenously into 4 normal subjects. Blood samples were obtained prior to the injection and at 1, 2, 4, 8 and 24 hr after the injection. Nuclear extracts and total cell lysates were prepared from MNC by standard techniques. IkappaB levels in MNC homogenates increased at 1 hr, peaked at 2-4 hr, started to decrease at 8 hr, and returned to baseline levels at 24 hr. NF-kappaB in MNC nuclear extracts decreased at 1 hr, reached a nadir at 4 hr, gradually increased at 8 hr and returned back to baseline levels at 24 hr. The total protein content of NF-kappaB subunit (P65) in MNC lysates also showed a decrease following hydrocortisone injection. This decrease was observed at 2 hr, reached a nadir at 4 hr, and returned to baseline levels at 24 hr. ROS generation inhibition paralleled NF-kappaB levels in the nucleus. It was inhibited at 1 hr, reached a nadir at 2-4 hr, started to increase at 8 hr, and returned to basal levels at 24 hr. Our data demonstrate that hydrocortisone induces IkappaB and suppresses NF-kappaB expression in MNC in parallel. IkappaB further reduces the translocation of NF-kappaB into the nucleus thus preventing the expression of proinflammatory genes.
authors.affiliation: Division of Endocrinology, State University of New York at Buffalo and Kaleida Health, 14209, USA.
authors.forename: A
authors.initials: A
authors.lastname: Aljada
authors.forename: H
authors.initials: H
authors.lastname: Ghanim
authors.forename: E
authors.initials: E
authors.lastname: Assian
authors.forename: P
authors.initials: P
authors.lastname: Mohanty
authors.forename: W
authors.initials: W
authors.lastname: Hamouda
authors.forename: R
authors.initials: R
authors.lastname: Garg
authors.forename: P
authors.initials: P
authors.lastname: Dandona
mesh_terms: D000328:Adult; D015153:Blotting, Western; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D006801:Humans; D006854:Hydrocortisone / Q000494:pharmacology*; D020672:I-kappa B Proteins; D015151:Immunoblotting; D007700:Kinetics; D007963:Leukocytes, Mononuclear / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D008875:Middle Aged; D016328:NF-kappa B / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D004268:DNA-Binding Proteins; D020672:I-kappa B Proteins; D016328:NF-kappa B; D017382:Reactive Oxygen Species; D006854:Hydrocortisone