Oxygen-independent stabilization of hypoxia inducible factor (HIF)-1 during RSV infection.

Background: Hypoxia-inducible factor 1 (HIF)-1alpha is a transcription factor that functions as master regulator of mammalian oxygen homeostasis. In addition, recent studies identified a role for HIF-1alpha as transcriptional regulator during inflammation or infection. Based on studies showing that respiratory syncytial virus (RSV) is among the most potent biological stimuli to induce an inflammatory milieu, we hypothesized a role of HIF-1alpha as transcriptional regulator during infections with RSV.

Hypoxia inducible factor-1 (HIF-1)-mediated repression of cystic fibrosis transmembrane conductance regulator (CFTR) in the intestinal epithelium.

Diarrhea is widespread in intestinal diseases involving ischemia and/or hypoxia. Since hypoxia alters stimulated Cl(-) and water flux, we investigated the influence of such a physiologically and pathophysiologically important signal on expression of the cystic fibrosis transmembrane conductance regulator (CFTR). Located on the apical membrane, this cAMP-activated Cl(-) channel determines salt and fluid transport across mucosal surfaces.

HIF-1-dependent repression of adenosine kinase attenuates hypoxia-induced vascular leak.

Extracellular adenosine has been implicated in vascular adaptation to hypoxia. Based on the observation that increases in intracellular adenosine can effectively elevate extracellular adenosine, we studied the contribution of adenosine kinase (AK, intracellular conversion of adenosine to adenosine monophosphate [AMP]) to vascular adenosine responses. Initial in vitro studies of ambient hypoxia revealed prominent repression of endothelial AK transcript (85% +/- 2% reduction), protein, and function.

Hypoxia inducible factor (HIF)-1 coordinates induction of Toll-like receptors TLR2 and TLR6 during hypoxia.

Background: During acute infection and inflammation, dramatic shifts in tissue metabolism are typical, thereby resulting in profound tissue hypoxia. Therefore, we pursued the hypothesis, that tissue hypoxia may influence innate immune responses by transcriptional modulation of Toll-like receptor (TLRs) expression and function.

Methodology/principal Findings: We gained first insight from transcriptional profiling of murine dendritic cells exposed to hypoxia (2% oxygen for 24 h).