Recombinant human interleukin (IL)-1 beta-mediated regulation of hypoxia-inducible factor-1 alpha (HIF-1 alpha) stabilization, nuclear translocation and activation requires an antioxidant/reactive oxygen species (ROS)-sensitive mechanism.
Cytokine-mediated regulation of hypoxia-inducible factor-1 alpha (HIF-1 alpha) non-hypoxic stabilization, translocation and activation is not well characterized. Furthermore, evidence that reactive oxygen species (ROS) signaling mediates interleukin (IL)-1 beta-dependent regulation of HIF-1 alpha has yet to be ascertained in alveolar epithelial cells. Recombinant human IL-1 beta induced, in a time-dependent manner, the nuclear translocation of HIF-1 alpha, an effect associated with up-regulating the activity of this transcription factor under normoxic conditions. In addition, analysis of the mode of action of IL-1 beta revealed a novel induction of intracellular ROS, including hydrogen peroxide (H(2)O(2)), the superoxide anion (O(2)(-*)) and the hydroxyl radical (*OH). The antioxidants, dimethyl sulfoxide (DMSO) and 1,3-dimethyl-2-thiourea (DMTU), purported to be prototypical scavengers of H2O2 and *OH, attenuated, in a dose-dependent manner, IL-1 beta-induced HIF-1 alpha nuclear translocation and activation. The NADPH-oxidase inhibitor, 4'-hydroxy-3'-methoxy-acetophenone (HMAP), which may affect mitochondrial ROS production, attenuated IL-1 beta-mediated nuclear translocation and activation of HIF-1 alpha. Inhibition of the mitochondrion complex I nicotinamide adenine dinucleotide phosphate-dependent oxidase by diphenylene iodonium (DPI), which blocks the conversion of ubiquinone --> ubiquinol, abrogated IL-1 beta-dependent nuclear translocation and activation of HIF-1 alpha. Similarly, interrupting the respiratory chain with potassium cyanide reversed the excitatory effect of IL-1 beta on HIF-1 alpha nuclear translocation and activation. These results indicate that a non-hypoxic pathway mediates cytokine-dependent regulation of HIF-1 alpha translocation and activation in a ROS-sensitive mechanism.
Haddad
John J
JJ
Neuroscience Research Laboratory, Department of Anesthesia & Perioperative Care, University of California at San Francisco, Medical Sciences Building S-261, San Francisco, California 94143, USA. haddadj@anesthesia.ucsf.edu
D021581:Active Transport, Cell Nucleus; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D002478:Cells, Cultured; D005333:Fetus; D006801:Humans; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007375:Interleukin-1 / Q000494:pharmacology*; D007700:Kinetics; D011650:Pulmonary Alveoli; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism; D011994:Recombinant Proteins / Q000494:pharmacology; D020545:Respiratory Mucosa / Q000187:drug effects / Q000502:physiology*; D014157:Transcription Factors / Q000378:metabolism*
D000975:Antioxidants; C497442:HIF1A protein, human; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007375:Interleukin-1; D017382:Reactive Oxygen Species; D011994:Recombinant Proteins; D014157:Transcription Factors