Lower phosphorylated glycogen synthase kinase-3B levels in platelets of patients with schizophrenia: increment by olanzapine treatment

Eur Arch Psychiatry Clin Neurosci. 2015 Mar;265(2):167-70. doi: 10.1007/s00406-014-0505-9. Epub 2014 May 15.

Abstract

Glycogen synthase kinase-3B (GSK-3B) is involved with important neuronal processes such as cell survival, gene regulation, mood and cognitive performance. This enzyme is inactivated by phosphorylation at the phospho-Ser9 site. We compared GSK-3B levels in patients with schizophrenia to a health control group. The levels of phosphorylated and total GSK-3B in platelets of ten drug-free patients, ten long-term olanzapine treated patients and 20 healthy controls were determined by means of an enzyme immunoassay kit. In drug-free patients, GSK-3B levels were accessed again after 8 weeks on treatment with olanzapine. At baseline, drug-free patients presented lower phosphorylated and total GSK-3B levels than healthy controls (p < 0.05). After 8 weeks on olanzapine treatment, phosphorylated and total GSK-3B levels were significantly increased (p < 0.01). Reduced phospho-Ser9-GSK-3B in schizophrenia may disrupt signal-transduction pathways and influence crucial cellular processes, such as transcription, apoptosis, stress response and cell proliferation. Further studies should clarify whether the increment of GSK-3B phosphorylation by olanzapine is related to its antipsychotic effects.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Antipsychotic Agents / therapeutic use*
  • Benzodiazepines / therapeutic use*
  • Blood Platelets / drug effects
  • Blood Platelets / enzymology*
  • Female
  • Gene Expression Regulation, Enzymologic / drug effects
  • Glycogen Synthase Kinase 3 / metabolism*
  • Humans
  • Male
  • Middle Aged
  • Olanzapine
  • Phosphorylation / drug effects
  • Psychiatric Status Rating Scales
  • Schizophrenia / blood*
  • Schizophrenia / drug therapy*
  • Statistics, Nonparametric
  • Time Factors

Substances

  • Antipsychotic Agents
  • Benzodiazepines
  • Glycogen Synthase Kinase 3
  • Olanzapine