title: Fluoxetine affects GluK2 editing, glutamate-evoked Ca(2+) influx and extracellular signal-regulated kinase phosphorylation in mouse astrocytes.
abstract: BACKGROUND
  We sought to study the effects of chronic exposure to fluoxetine - a selective serotonin reuptake inhibitor (SSRI) and specific 5-HT(2B) receptor agonist in astrocytes - on the expression of kainate receptors (GluK1-5) in cultured astrocytes and in intact brains in mice and on GluK2 editing by adenosine deaminase acting on RNA (ADAR), as well as the ensuing effects of fluoxetine on glutamate-mediated Ca(2+) influx and extracellular signal-regulated kinase (ERK)(1/2) phosphorylation in astrocytes.
  
  
  METHODS
  We performed reverse transcription-polymerase chain reaction (PCR) to assess mRNA expression. We analyzed RNA editing with amplification refractory mutation system PCR and complementary DNA sequencing. Protein expression and ERK phosphorylation were assessed using Western blots. We studied gene silencing with specific small interfering RNAs (siRNA), and we studied intracellular Ca(2+) using fluorometry.
  
  
  RESULTS
  All GluK subunits were present in the brain in vivo, and GluK2-5 subunits were present in cultured astrocytes. Fluoxetine upregulated GluK2 and ADAR2. Enhanced GluK2 editing by fluoxetine abolished glutamate-mediated increases in intra cellular Ca(2+) and ERK(1/2) phosphorylation. Enhanced editing of GluK2 was prevented by siRNA against the 5-HT(2B) receptor or ADAR2.
  
  
  CONCLUSIONS
  Limitations of our study include the use of an in vitro system, but our cultured cells in many respects behave like in vivo astrocytes.
  
  
  CONCLUSIONS
  Fluoxetine alters astrocytic glutamatergic function.
authors.affiliation: Department of Clinical Pharmacology, College of Basic Medical Sciences, China Medical University, Shenyang, China.
authors.forename: Baoman
authors.initials: B
authors.lastname: Li
authors.forename: Shiquen
authors.initials: S
authors.lastname: Zhang
authors.forename: Hongyan
authors.initials: H
authors.lastname: Zhang
authors.forename: Leif
authors.initials: L
authors.lastname: Hertz
authors.forename: Liang
authors.initials: L
authors.lastname: Peng
mesh_terms: D000243:Adenosine Deaminase / Q000378:metabolism; D000818:Animals; D021461:Animals, Outbred Strains; D001921:Brain / Q000378:metabolism; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005473:Fluoxetine / Q000494:pharmacology*; D020868:Gene Silencing / Q000187:drug effects; D018698:Glutamic Acid / Q000494:pharmacology; D008297:Male; D051379:Mice; D010766:Phosphorylation / Q000187:drug effects; D017393:RNA Editing / Q000187:drug effects; D034741:RNA, Small Interfering / Q000494:pharmacology; D044403:Receptor, Serotonin, 5-HT2B / Q000378:metabolism; D018092:Kainic Acid Receptors / Q000096:biosynthesis*; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects; D015854:Up-Regulation
chemical_list: D000243:Adenosine Deaminase; D002118:Calcium; D048049:Extracellular Signal-Regulated MAP Kinases; D005473:Fluoxetine; D018698:Glutamic Acid; D034741:RNA, Small Interfering; D044403:Receptor, Serotonin, 5-HT2B; D018092:Kainic Acid Receptors; D017367:Selective Serotonin Reuptake Inhibitors