The early stage formation of PI3K-AMPAR GluR2 subunit complex facilitates the long term neuroprotection induced by propofol post-conditioning in rats

PLoS One. 2013 Jun 11;8(6):e65187. doi: 10.1371/journal.pone.0065187. Print 2013.

Abstract

Previously, we have shown that the phosphoinositide-3-kinase (PI3K) mediated acute (24 h) post-conditioning neuroprotection induced by propofol. We also found that propofol post-conditioning produced long term neuroprotection and inhibited the internalization of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor GluR2 subunit up to 28 days post middle cerebral artery occlusion (MCAO). However, the relationship between PI3K with AMPA receptor GluR2 subunit trafficking in propofol post-conditioning has never been explored. Here we showed that propofol post-conditioning promoted the binding of PI3K to the C-terminal of AMPA receptor GluR2 subunit and formed a complex within 1 day after transient MCAO. Interestingly, the enhanced activity of PI3K was observed in the hippocampus of post-conditioning rats at day 1 post ischemia, whereas the decrease of AMPA receptor GluR2 subunit internalization was found up to 28 days in the same group. Administration of PI3K selective antagonist wortmannin inhibited the improvement of spatial learning memory and the increase of neurogenesis in the dentate gyrus up to 28 days post ischemia. It also reversed the inhibition of AMPA receptor GluR2 internalization induced by propofol post-conditioning. Together, our data indicated the critical role of PI3K in regulating the long term neuroprotection induced by propofol post-conditioning. Moreover, this role was established by first day activation of PI3K and formation of PI3K-AMPA receptor GluR2 complex, thus stabilized the structure of postsnaptic AMPA receptor and inhibited the internalization of GluR2 subunit during the early stage of propofol post-conditioning.

Publication types

  • Research Support, Non-U.S. Gov't
  • Retracted Publication

MeSH terms

  • Androstadienes / pharmacology
  • Animals
  • Blotting, Western
  • Cerebral Arterial Diseases / metabolism
  • Hippocampus / cytology
  • Hippocampus / drug effects*
  • Hypnotics and Sedatives / pharmacology
  • Immunoblotting
  • Immunoprecipitation
  • Male
  • Neurogenesis / drug effects
  • Phosphatidylinositol 3-Kinases / metabolism*
  • Phosphoinositide-3 Kinase Inhibitors
  • Propofol / pharmacology*
  • Protein Binding
  • Protein Kinase Inhibitors / pharmacology
  • Rats
  • Rats, Sprague-Dawley
  • Receptors, AMPA / metabolism*
  • Wortmannin

Substances

  • Androstadienes
  • Hypnotics and Sedatives
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Kinase Inhibitors
  • Receptors, AMPA
  • Wortmannin
  • Propofol

Grants and funding

This work was supported by Natural Science Foundation of China (81071059, 81100984, 30972847), Science and Technology Supported Key Project of Tianjin (12ZCZDSY03000), Scientific Grant from Tianjin Health Bureau (09KZ106). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.