Hydrogen sulfide protects PC12 cells against reactive oxygen species and extracellular signal-regulated kinase 1/2-mediated downregulation of glutamate transporter-1 expression induced by chemical hypoxia

Int J Mol Med. 2012 Nov;30(5):1126-32. doi: 10.3892/ijmm.2012.1090. Epub 2012 Aug 8.

Abstract

Hypoxia and/or ischemia are implicated in neurodegenerative disorders. In these diseases, hypoxia/ischemia may induce oxidative stress, including production of reactive oxygen species (ROS), which result in a decrease in glutamate transporter expression. Hydrogen sulfide (H2S), as the third gasotransmitter, has neuroprotective effects and potent antioxidant properties. In the present study, we investigated the role of glutamate transporter-1 (GLT-1) in the protection of H2S against chemical hypoxia-induced injury in PC12 cells. We found that cobalt chloride (CoCl2), a chemical hypoxia agent, reduced the expression of GLT-1 in a time-dependent manner. Pretreatment with NaHS (a donor of H2S) reversed the CoCl2-induced downregulation of GLT-1 expression. Pretreatment with DHK (a selective inhibitor of GLT-1) for 30 min prior to NaHS preconditioning significantly inhibited the cytoprotection of H2S against CoCl2-induced injuries, leading to an increase in cytotoxicity and apoptosis as well as to a loss of mitochondrial membrane potential (MMP). In addition, we found that similar to the effect of NaHS, pretreatment with NAC (a ROS scavenger) or U0126 (a MEK1/2 inhibitor) blocked the downregulation of GLT-1 expression induced by CoCl2. Collectively, we demonstrated for the first time that ROS and extracellular signal-regulated kinase 1/2 (ERK1/2)-mediated reduction of GLT-1 expression may be involved in chemical hypoxia-induced neural injury and that H2S attenuates this injury partly by upregulating GLT-1 expression in PC12 cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Cell Hypoxia / drug effects
  • Cell Survival / drug effects
  • Cobalt / pharmacology
  • Down-Regulation / drug effects*
  • Excitatory Amino Acid Transporter 2 / antagonists & inhibitors
  • Excitatory Amino Acid Transporter 2 / genetics*
  • Excitatory Amino Acid Transporter 2 / metabolism
  • Extracellular Signal-Regulated MAP Kinases / metabolism*
  • Extracellular Signal-Regulated MAP Kinases / physiology
  • Hydrogen Sulfide / pharmacology*
  • Kainic Acid / analogs & derivatives
  • Kainic Acid / pharmacology
  • MAP Kinase Signaling System
  • Neuroprotective Agents / pharmacology*
  • PC12 Cells
  • Rats
  • Reactive Oxygen Species / metabolism*

Substances

  • Excitatory Amino Acid Transporter 2
  • Neuroprotective Agents
  • Reactive Oxygen Species
  • Cobalt
  • dihydrokainic acid
  • Extracellular Signal-Regulated MAP Kinases
  • cobaltous chloride
  • Kainic Acid
  • Hydrogen Sulfide