We investigated the expression and the role of hypoxia-inducible factor 1alpha (HIF-1alpha) on the desferrioxamine (DFX)-induced cytokine production in human mast cells, HMG-1 cells. HIF- 1alpha mRNA was constitutively expressed in mast cell lines including the P815, RBL-2H3. and HMC-1. DFX (100 muM) resulted in a great increase in protein levels of HIF-1alpha in HMC-1 cells, but it did not affect HIF-1alpha mRNA expression. Iron (HIF-1 inhibitor) inhibited increase of HIF-1alpha and NF-kappaB protein levels. Pyrriolidine-dithiocarbamate (PDTC. NF-kappaB inhibitor) inhibited increase of NF-kappaB protein levels, but it slightly increased HIF-1alpha protein levels. In addition. DFX significantly increased the production of IL-6, IL-8, and TNF-alpha in HMC-1 (P < 0.05). These increased cytokine levels were significantly inhibited by treatment of iron or PDTC in a dose-dependent manner (P < 0.05). We demonstrated the regulatory effects of HIF-1alpha on the DFX-induced proinflammatory cytokine production in human mast cells for the first time. These data indicate that inflammatory cytokines seem to be under HIF-1alpha or NF-kappaB transcriptional regulation in the hypoxic conditions on mast cells. (C) 2003 Elsevier Science (USA). All rights reserved.