Regulation of annexin I in rheumatoid synovial cells by glucocorticoids and interleukin-1

Abstract

The glucocorticoid (GC)-induced antiinflammatory molecule annexin I is expressed in leukocytes and has antiinflammatory effects in animal models of arthritis, but the expression of annexin I in rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) is unknown. We report the constitutive and dexamethasone (DEX)-inducible expression of annexin I in RA FLS. DEX increased FLS annexin I protein translocation and mRNA expression. Interleukin (IL)-1? also induced annexin I translocation and mRNA but also increased intracellular protein. DEX and IL-1 had additive effects on annexin I mRNA, but DEX inhibited the inducing effect of IL-1? on cell surface annexin I. These results indicate that glucocorticoids and IL-1? upregulate the synthesis and translocation of annexin I in RA FLS, but interdependent signalling pathways are involved. Copyright © 2006 Eric F. Morand et al.