Involvement of TREK-1 activity in astrocyte function and neuroprotection under simulated ischemia conditions

J Mol Neurosci. 2013 Mar;49(3):499-506. doi: 10.1007/s12031-012-9875-5. Epub 2012 Aug 16.

Abstract

Astrocytes play a fundamental role in the pathogenesis of ischemic neuronal death. The optimal operation of electrogenic astrocytic transporters and exchangers for some well-defined astrocyte brain homeostatic functions depends on the presence of K(+) channels in the cell membranes and the hyperpolarized membrane potential. Our previous study showed that astrocytes functionally express two-pore domain K(+) channel TREK-1, which helps to set the negative resting membrane potential. However, the roles of TREK-1 on astrocytic function under normal and ischemic conditions remain unclear. In this study, we investigated the expression of TREK-1 protein on cultured astrocytes and the effect of TREK-1 activity on astrocytic glutamate clearance capacity and release of s100β after simulated ischemic insult. TREK-1 immunoreactivity was up-regulated after hypoxia. Suppression of TREK-1 activity inhibited the glutamate clearance capability, enhanced the inflammatory secretion of astrocytes derived s100β and led to increased neuronal apoptosis after ischemic insult. Our results suggest that TREK-1 activity is involved in astrocytic function and neuronal survival. This would provide evidence showing astrocytic TREK-1 involvement in ischemia pathology which may serve as a potential therapeutic target in stroke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / drug effects
  • Astrocytes / cytology
  • Astrocytes / drug effects
  • Astrocytes / metabolism
  • Astrocytes / physiology*
  • Bupivacaine / pharmacology
  • Cell Hypoxia / genetics
  • Cell Hypoxia / physiology*
  • Cells, Cultured / drug effects
  • Cells, Cultured / metabolism
  • Cerebral Cortex / cytology
  • Coculture Techniques
  • Culture Media, Serum-Free
  • Gene Expression Regulation
  • Glutamic Acid / metabolism
  • Homeostasis
  • Ischemia / metabolism*
  • Nerve Growth Factors / metabolism
  • Nerve Tissue Proteins / biosynthesis
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / physiology*
  • Neurons / cytology
  • Potassium Channels, Tandem Pore Domain / biosynthesis
  • Potassium Channels, Tandem Pore Domain / genetics
  • Potassium Channels, Tandem Pore Domain / physiology*
  • Quinine / pharmacology
  • Rats
  • S100 Calcium Binding Protein beta Subunit
  • S100 Proteins / metabolism

Substances

  • Culture Media, Serum-Free
  • Nerve Growth Factors
  • Nerve Tissue Proteins
  • Potassium Channels, Tandem Pore Domain
  • S100 Calcium Binding Protein beta Subunit
  • S100 Proteins
  • potassium channel protein TREK-1
  • Glutamic Acid
  • Quinine
  • Bupivacaine