Hypoxia-inducible factor (HIF) prolyl hydroxylase inhibitors induce autophagy and have a protective effect in an in-vitro ischaemia model

Sci Rep. 2020 Jan 31;10(1):1597. doi: 10.1038/s41598-020-58482-w.

Abstract

This study compared effects of five hypoxia-inducible factor (HIF) prolyl hydroxylases (PHD) inhibitors on PC12 cells and primary rat neurons following oxygen-glucose deprivation (OGD). At 100 µM, the PHD inhibitors did not cause cytotoxicity and apoptosis. MTT activity was only significantly reduced by FG4592 or Bayer 85-3934 in PC12 cells. The PHD inhibitors at 100 µM significantly increased the LC3-II/LC3-I expression ratio and downregulated p62 in PC12 cells, so did FG4592 (30 µM) and DMOG (100 µM) in neurons. HIF-1α was stabilised in PC12 cells by all the PHD inhibitors at 100 µM except for DMOG, which stabilised HIF-1α at 1 and 2 mM. In primary neurons, HIF-1α was stabilised by FG4592 (30 µM) and DMOG (100 µM). Pretreatment with the PHD inhibitors 24 hours followed by 24 hour reoxygenation prior to 6 hours OGD (0.3% O2) significantly reduced LDH release and increased MTT activity compared to vehicle (1% DMSO) pretreatment. In conclusion, the PHD inhibitors stabilise HIF-1α in normoxia, induce autophagy, and protect cells from a subsequent OGD insult. The new class of PHD inhibitors (FG4592, FG2216, GSK1278863, Bay85-3934) have the higher potency than DMOG. The interplay between autophagy, HIF stabilisation and neuroprotection in ischaemic stroke merits further investigation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids, Dicarboxylic / pharmacology
  • Animals
  • Autophagy / drug effects*
  • Barbiturates / pharmacology
  • Flow Cytometry
  • Fluorescent Antibody Technique
  • Gene Expression / drug effects
  • Glycine / analogs & derivatives
  • Glycine / pharmacology
  • Hypoxia-Inducible Factor 1, alpha Subunit / metabolism
  • Hypoxia-Inducible Factor-Proline Dioxygenases / antagonists & inhibitors*
  • Ischemia / drug therapy*
  • Ischemia / metabolism
  • Neurons / drug effects
  • Neurons / metabolism
  • PC12 Cells / drug effects
  • Rats
  • Real-Time Polymerase Chain Reaction

Substances

  • Amino Acids, Dicarboxylic
  • Barbiturates
  • GSK1278863
  • Hif1a protein, rat
  • Hypoxia-Inducible Factor 1, alpha Subunit
  • Hypoxia-Inducible Factor-Proline Dioxygenases
  • Glycine
  • oxalylglycine