Activation of the prolyl hydroxylase oxygen-sensor results in induction of GLUT1, heme oxygenase-1, and nitric-oxide synthase proteins and confers protection from metabolic inhibition to cardiomyocytes

J Biol Chem. 2003 May 30;278(22):20235-9. doi: 10.1074/jbc.M301391200. Epub 2003 Mar 20.

Abstract

Recently an oxygen-sensing/transducing mechanism has been identified as a family of O2-dependent prolyl hydroxylase domain-containing enzymes (PHD). In normoxia, PHD hydroxylates a specific proline residue that directs the degradation of constitutively synthesized hypoxia-inducible factor-1alpha. During hypoxia, the cessation of hydroxylation of this proline results in less degradation and thus increases hypoxia-inducible factor-1alpha protein levels. In this study we have examined the consequences of activating the PHD oxygen-sensing pathway in cultured neonatal myocytes using ethyl-3,4 dihydroxybenzoate and dimethyloxalylglycine, inhibitors that, similar to hypoxia, inhibit this family of O2-dependent PHD enzymes. Increased glucose uptake and enhanced glycolytic metabolism are classical cellular responses to hypoxia. Ethyl-3,4 dihydroxybenzoate treatment of cardiomyocyte cultures for 24 h increased [3H]deoxy-4-glucose uptake concurrent with an induction of GLUT1 protein. In addition, ethyl-3,4 dihydroxybenzoate, dimethyloxalylglycine, and hypoxia treatments were found to induce protein levels of nitricoxide synthase-2 and heme oxygenase-1, two important cardioregulatory proteins whose expression in response to hypoxic conditions is poorly understood. In conjunction with these changes in gene expression, activation of the PHD oxygen-sensing mechanism was found to preserve myocyte viability in the face of metabolic inhibition with cyanide and 2-deoxyglucose. These results point to a key role for the PHD pathway in the phenotypic changes that are observed in a hypoxic myocyte and may suggest a strategy to pharmacologically induce protection in heart.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Base Sequence
  • DNA Primers
  • Enzyme Activation
  • Enzyme Inhibitors / pharmacology
  • Glucose / metabolism
  • Heme Oxygenase (Decyclizing) / biosynthesis*
  • Mice
  • Myocardium / cytology
  • Myocardium / enzymology
  • Myocardium / metabolism*
  • Nitric Oxide Synthase / biosynthesis*
  • Nitric Oxide Synthase / genetics
  • Nitric Oxide Synthase Type II
  • Oxygen / metabolism*
  • Polymerase Chain Reaction
  • Procollagen-Proline Dioxygenase / antagonists & inhibitors
  • Procollagen-Proline Dioxygenase / metabolism*
  • RNA, Messenger / genetics

Substances

  • DNA Primers
  • Enzyme Inhibitors
  • RNA, Messenger
  • Procollagen-Proline Dioxygenase
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse
  • Heme Oxygenase (Decyclizing)
  • Glucose
  • Oxygen