Contribution of epithelial innate immunity to systemic protection afforded by prolyl hydroxylase inhibition in murine colitis

Mucosal Immunol. 2014 Jan;7(1):114-23. doi: 10.1038/mi.2013.29. Epub 2013 May 22.

Abstract

Pharmacological stabilization of hypoxia-inducible factor (HIF) through prolyl hydroxylase (PHD) inhibition limits mucosal damage associated with models of murine colitis. However, little is known about how PHD inhibitors (PHDi) influence systemic immune function during mucosal inflammation or the relative importance of immunological changes to mucosal protection. We hypothesized that PHDi enhances systemic innate immune responses to colitis-associated bacteremia. Mice with colitis induced by trinitrobenzene sulfonic acid were treated with AKB-4924, a new HIF-1 isoform-predominant PHDi, and clinical, immunological, and biochemical endpoints were assessed. Administration of AKB-4924 led to significantly reduced weight loss and disease activity compared with vehicle controls. Treated groups were pyrexic but did not become subsequently hypothermic. PHDi treatment augmented epithelial barrier function and led to an approximately 50-fold reduction in serum endotoxin during colitis. AKB-4924 also decreased cytokines involved in pyrogenesis and hypothermia, significantly reducing serum levels of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α while increasing IL-10. Treatment offered no protection against colitis in epithelial-specific HIF-1α-deficient mice, strongly implicating epithelial HIF-1α as the tissue target for AKB-4924-mediated protection. Taken together, these results indicate that inhibition of prolyl hydroxylase with AKB-4924 enhances innate immunity and identifies that the epithelium is a central site of inflammatory protection afforded by PHDi in murine colitis.

Publication types

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

MeSH terms

  • Animals
  • Colitis / chemically induced
  • Colitis / drug therapy
  • Colitis / immunology*
  • Colitis / metabolism*
  • Disease Models, Animal
  • Endotoxemia / drug therapy
  • Female
  • Hypoxia-Inducible Factor 1 / agonists
  • Hypoxia-Inducible Factor 1, alpha Subunit / agonists
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Immunity, Innate / drug effects*
  • Immunity, Mucosal / drug effects*
  • Intestinal Mucosa / immunology*
  • Intestinal Mucosa / metabolism*
  • Mice
  • Permeability / drug effects
  • Piperazines / administration & dosage
  • Piperazines / pharmacology
  • Prolyl Hydroxylases / metabolism*
  • Prolyl-Hydroxylase Inhibitors / pharmacology*
  • Pyridones / administration & dosage
  • Pyridones / pharmacology
  • Trinitrobenzenesulfonic Acid / adverse effects
  • Tumor Necrosis Factor-alpha / genetics
  • Tumor Necrosis Factor-alpha / metabolism

Substances

  • AKB-4924
  • Hypoxia-Inducible Factor 1
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Piperazines
  • Prolyl-Hydroxylase Inhibitors
  • Pyridones
  • Tumor Necrosis Factor-alpha
  • Trinitrobenzenesulfonic Acid
  • Prolyl Hydroxylases