The role of AKT1 and autophagy in the protective effect of hydrogen sulphide against hepatic ischemia/reperfusion injury in mice

Autophagy. 2012 Jun;8(6):954-62. doi: 10.4161/auto.19927. Epub 2012 Jun 1.

Abstract

Hydrogen sulphide (H 2S) exerts a protective effect in hepatic ischemia-reperfusion (I/R) injury. However, the exact mechanism of H 2S action remains largely unknown. This study was designed to investigate the role of the PtdIns3K-AKT1 pathways and autophagy in the protective effect of H 2S against hepatic I/R injury. Primary cultured mouse hepatocytes and livers with or without NaHS (a donor of H 2S) preconditioning were exposed to anoxia/reoxygenation (A/R) and I/R, respectively. In certain groups, they were also pretreated with LY294002 (AKT1-specific inhibitor), 3-methyladenine (3MA, autophagy inhibitor) or rapamycin (autophagy enhancer), alone or simultaneously. Cell viability, expression of P-AKT1, T-AKT1, LC3 and BECN1 were examined. The severity of liver injury was measured by the levels of serum aminotransferase and inflammatory cytokine, apoptosis and histological examination. GFP-LC3 redistribution and transmission electron microscopy were used to test the activity of autophagy. H 2S preconditioning activated PtdIns3K-AKT1 signaling in hepatocytes. LY294002 could abolish the AKT1 activation and attenuate the protective effect of H 2S on hepatocytes A/R and hepatic I/R injuries. H 2S suppressed hepatic autophagy in vitro and in vivo. Further reducing autophagy by 3MA also diminished the protective effect of H 2S, while rapamycin could reverse the autophagy inhibitory effect and enhance the protective effect of H 2S against hepatocytes A/R and hepatic I/R injuries, consequently. Taken together, H 2S protects against hepatocytic A/R and hepatic I/R injuries, at least in part, through AKT1 activation but not autophagy. An autophagy agonist could be applied to potentiate this hepatoprotective effect by reversing the autophagy inhibition of H 2S.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Autophagy* / drug effects
  • Cytokines / metabolism
  • Cytoprotection / drug effects
  • Hepatocytes / drug effects
  • Hepatocytes / enzymology
  • Hepatocytes / pathology
  • Hepatocytes / ultrastructure
  • Hydrogen Sulfide / administration & dosage
  • Hydrogen Sulfide / pharmacology*
  • Hydrogen Sulfide / therapeutic use
  • Inflammation Mediators / metabolism
  • Liver / drug effects
  • Liver / enzymology*
  • Liver / pathology*
  • Liver / ultrastructure
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Phosphatidylinositol 3-Kinases / metabolism
  • Protective Agents / administration & dosage
  • Protective Agents / pharmacology
  • Proto-Oncogene Proteins c-akt / antagonists & inhibitors
  • Proto-Oncogene Proteins c-akt / metabolism*
  • Reperfusion Injury / drug therapy
  • Reperfusion Injury / enzymology
  • Reperfusion Injury / pathology*
  • Reperfusion Injury / prevention & control*
  • Signal Transduction / drug effects
  • Vacuoles / drug effects
  • Vacuoles / metabolism
  • Vacuoles / ultrastructure

Substances

  • Cytokines
  • Inflammation Mediators
  • Protective Agents
  • Phosphatidylinositol 3-Kinases
  • Akt1 protein, mouse
  • Proto-Oncogene Proteins c-akt
  • Hydrogen Sulfide