HIF-1α regulates epithelial inflammation by cell autonomous NFκB activation and paracrine stromal remodeling

M Scortegagna, C Cataisson, RJ Martin… - Blood, The Journal …, 2008 - ashpublications.org
M Scortegagna, C Cataisson, RJ Martin, DJ Hicklin, RD Schreiber, SH Yuspa, JM Arbeit
Blood, The Journal of the American Society of Hematology, 2008ashpublications.org
Abstract Hypoxia inducible factor-1 (HIF-1) is a master regulatory transcription factor
controlling multiple cell-autonomous and non–cell-autonomous processes, such as
metabolism, angiogenesis, matrix invasion, and cancer metastasis. Here we used a new line
of transgenic mice with constitutive gain of HIF-1 function in basal keratinocytes and
demonstrated a signaling pathway from HIF-1 to nuclear factor κ B (NFκB) activation to
enhanced epithelial chemokine and cytokine elaboration. This pathway was responsible for …
Abstract
Hypoxia inducible factor-1 (HIF-1) is a master regulatory transcription factor controlling multiple cell-autonomous and non–cell-autonomous processes, such as metabolism, angiogenesis, matrix invasion, and cancer metastasis. Here we used a new line of transgenic mice with constitutive gain of HIF-1 function in basal keratinocytes and demonstrated a signaling pathway from HIF-1 to nuclear factor κ B (NFκB) activation to enhanced epithelial chemokine and cytokine elaboration. This pathway was responsible for a phenotypically silent accumulation of stromal inflammatory cells and a marked inflammatory hypersensitivity to a single 12-O-tetradecanoylphorbol-13-acetate (TPA) challenge. HIF-1–induced NFκB activation was composed of 2 elements, IκB hyperphosphorylation and phosphorylation of Ser276 on p65, enhancing p65 nuclear localization and transcriptional activity, respectively. NFκB transcriptional targets macrophage inflammatory protein-2 (MIP-2/CXCL2/3), keratinocyte chemokine (KC/CXCL1), and tumor necrosis factor [alfa] (TNFα) were constitutively up-regulated and further increased after TPA challenge both in cultured keratinocytes and in transgenic mice. Whole animal KC, MIP-2, or TNFα immunodepletion each abrogated TPA-induced inflammation, whereas blockade of either VEGF or placenta growth factor (PlGF) signaling did not affect transgenic inflammatory hyper-responsiveness. Thus, epithelial HIF-1 gain of function remodels the local environment by cell-autonomous NFκB-mediated chemokine and cytokine secretion, which may be another mechanism by which HIF-1 facilitates either inflammatory diseases or malignant progression.
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