Dexmedetomidine attenuates propofol-induce neuroapoptosis partly via the activation of the PI3k/Akt/GSK3β pathway in the hippocampus of neonatal rats

Environ Toxicol Pharmacol. 2017 Jun:52:121-128. doi: 10.1016/j.etap.2017.03.017. Epub 2017 Mar 28.

Abstract

Recent studies have demonstrated that propofol causes neurodegeneration in developing brains. Evidence has shown that dexmedetomidine has neuroprotective effects. However, whether dexmedetomidine can reduce propofol-induced neuroapoptosis and by what mechanisms it acts remain unclear. We investigated whether dexmedetomidine can attenuate propofol-induced neuroapoptosis by disturbing the PI3K/Akt/GSK3β pathway during brain development. Seven-day-old rats were randomly exposed to 100mg/kg propofol and 100mg/kg propofol plus different doses of dexmedetomidine or 100mg/kg propofol and 75μg/kg dexmedetomidine plus PI3K inhibitor LY294002 or GSK3β inhibitor TDZD-8. TEM and TUNEL were used to detect neuronal structure changes and apoptosis. The expression of phospho-Akt, phospho-GSK3β, Akt and GSK3β were quantified using western blots and immunofluorescence. Pretreatment with different doses of dexmedetomidine protected against propofol-induced neuroapoptosis. Furthermore, propofol decreased the levels of phospho-Akt and phospho-GSK3β, whereas dexmedetomidine partially reversed this inhibition. In addition, treatment with LY294002 inhibited the neuroprotection of dexmedetomidine, whereas TDZD-8 enhanced neuroprotection. Our results indicate that dexmedetomidine prevents propofol-induced neuroapoptosis by increasing the levels of phospho-Akt and phospho-GSK3β.

Keywords: AKT; Apoptosis; Dexmedetomidine; GSK3β; Propofol.

MeSH terms

  • Anesthetics, Intravenous / toxicity*
  • Animals
  • Animals, Newborn
  • Apoptosis / drug effects
  • Chromones / pharmacology
  • Dexmedetomidine / pharmacology*
  • Female
  • Glycogen Synthase Kinase 3 beta / antagonists & inhibitors
  • Glycogen Synthase Kinase 3 beta / metabolism
  • Hippocampus / drug effects*
  • Hippocampus / metabolism
  • Hippocampus / pathology
  • Male
  • Morpholines / pharmacology
  • Neurons / drug effects
  • Neurons / pathology
  • Neuroprotective Agents / pharmacology*
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoinositide-3 Kinase Inhibitors
  • Propofol / toxicity*
  • Proto-Oncogene Proteins c-akt / metabolism
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects
  • Thiadiazoles / pharmacology

Substances

  • 4-benzyl-2-methyl-1,2,4-thiadiazolidine-3,5-dione
  • Anesthetics, Intravenous
  • Chromones
  • Morpholines
  • Neuroprotective Agents
  • Phosphoinositide-3 Kinase Inhibitors
  • Thiadiazoles
  • 2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one
  • Dexmedetomidine
  • Glycogen Synthase Kinase 3 beta
  • Proto-Oncogene Proteins c-akt
  • Propofol