HIF-1alpha regulates epithelial inflammation by cell autonomous NFkappaB activation and paracrine stromal remodeling

Blood. 2008 Apr 1;111(7):3343-54. doi: 10.1182/blood-2007-10-115758. Epub 2008 Jan 16.

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 kappa B (NFkappaB) 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 NFkappaB activation was composed of 2 elements, IkappaB hyperphosphorylation and phosphorylation of Ser276 on p65, enhancing p65 nuclear localization and transcriptional activity, respectively. NFkappaB transcriptional targets macrophage inflammatory protein-2 (MIP-2/CXCL2/3), keratinocyte chemokine (KC/CXCL1), and tumor necrosis factor [alfa] (TNFalpha) were constitutively up-regulated and further increased after TPA challenge both in cultured keratinocytes and in transgenic mice. Whole animal KC, MIP-2, or TNFalpha 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 NFkappaB-mediated chemokine and cytokine secretion, which may be another mechanism by which HIF-1 facilitates either inflammatory diseases or malignant progression.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus / drug effects
  • Active Transport, Cell Nucleus / genetics
  • Animals
  • Carcinogens / toxicity
  • Cell Nucleus / genetics
  • Cell Nucleus / metabolism*
  • Cell Nucleus / pathology
  • Cytokines / genetics
  • Cytokines / metabolism
  • Drug Hypersensitivity / genetics
  • Drug Hypersensitivity / metabolism*
  • Drug Hypersensitivity / pathology
  • Epithelium / metabolism
  • Epithelium / pathology
  • Hypoxia-Inducible Factor 1, alpha Subunit / genetics
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism*
  • Inflammation / chemically induced
  • Inflammation / genetics
  • Inflammation / metabolism
  • Inflammation / pathology
  • Keratinocytes / metabolism*
  • Keratinocytes / pathology
  • Mice
  • Mice, Transgenic
  • Paracrine Communication* / drug effects
  • Paracrine Communication* / genetics
  • Phosphorylation / drug effects
  • Signal Transduction / drug effects
  • Signal Transduction / genetics
  • Stromal Cells / metabolism
  • Stromal Cells / pathology
  • Tetradecanoylphorbol Acetate / toxicity
  • Transcription Factor RelA / genetics
  • Transcription Factor RelA / metabolism*
  • Transcription, Genetic / drug effects
  • Transcription, Genetic / genetics
  • Up-Regulation / drug effects
  • Up-Regulation / genetics

Substances

  • Carcinogens
  • Cytokines
  • Hif1a protein, mouse
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Transcription Factor RelA
  • Tetradecanoylphorbol Acetate