Antisense oligonucleotide against GTPase Rab5b inhibits metabotropic agonist DHPG-induced neuroprotection

Brain Res. 2004 Nov 26;1028(1):59-65. doi: 10.1016/j.brainres.2004.08.064.


(S)-3,5-dihydroxyphenylglycine (DHPG), a group I metabotropic glutamate receptor (mGluR1 and 5) agonist reduced NMDA-mediated membrane currents, NMDA-induced cell death and up-regulated Rab5b, a small GTPase involved in endocytosis [M. Blaabjerg, A. Baskys, J. Zimmer and M. P. Vawter, Changes in hippocampal gene expression after neuroprotective activation of group I metabotropic glutamate receptors, Molec. Brain Res. 117 (2003) 196-205; M. Blaabjerg, L. Fang, J. Zimmer and A. Baskys, Neuroprotection against NMDA excitotoxicity by group I metabotropic glutamate receptors is associated with reduction of NMDA stimulated currents, Experimental Neurol. 183 (2003) 573-580.]. To examine the role of Rab5b on DHPG-mediated neuroprotection in organotypic hippocampal cultures, we developed antisense oligonucleotide targeted to suppress Rab5b translation. Treatment of cultures with the antisense (24 h) but not scrambled sequence oligonucleotide suppressed DHPG-induced increase in Rab5b expression and significantly disrupted DHPG-induced protection against NMDA toxicity in a concentration-dependent manner (0.01-10 nM). Antisense but not scrambled oligonucleotide treatment reduced NMDA toxicity (to 74.4+/-5.9% of control) and this effect could be blocked by protein kinase C inhibitor staurosporine (0.2 microM) or with the protease inhibitor leupeptin (100 microM). Application of osmotic shock followed by K(+) depletion to disrupt endocytosis abolished the protective effect of DHPG. These data suggest that neuroprotection by DHPG against NMDA-mediated injury may involve facilitation of NMDA receptor endocytosis likely stimulated by DHPG-induced increase in Rab5b synthesis.

Publication types

  • Comparative Study

MeSH terms

  • Animals
  • Dose-Response Relationship, Drug
  • Drug Antagonism
  • Endocytosis / drug effects
  • Gene Expression / drug effects
  • Hippocampus / drug effects
  • Hippocampus / metabolism*
  • Methoxyhydroxyphenylglycol / analogs & derivatives*
  • Methoxyhydroxyphenylglycol / pharmacology*
  • N-Methylaspartate / toxicity
  • Neuroprotective Agents / pharmacology*
  • Oligonucleotides, Antisense / pharmacology
  • Organ Culture Techniques
  • Rats
  • Rats, Wistar
  • Receptors, Metabotropic Glutamate / agonists
  • Receptors, Metabotropic Glutamate / metabolism*
  • Receptors, N-Methyl-D-Aspartate / metabolism
  • rab5 GTP-Binding Proteins / genetics
  • rab5 GTP-Binding Proteins / metabolism*


  • Neuroprotective Agents
  • Oligonucleotides, Antisense
  • Receptors, Metabotropic Glutamate
  • Receptors, N-Methyl-D-Aspartate
  • Methoxyhydroxyphenylglycol
  • N-Methylaspartate
  • rab5 GTP-Binding Proteins
  • 3,4-dihydroxyphenylglycol