Transcriptome Alterations in Prefrontal Pyramidal Cells Distinguish Schizophrenia From Bipolar and Major Depressive Disorders

Biol Psychiatry. 2017 Oct 15;82(8):594-600. doi: 10.1016/j.biopsych.2017.03.018. Epub 2017 Apr 4.

Abstract

Background: Impairments in certain cognitive processes (e.g., working memory) are typically most pronounced in schizophrenia (SZ), intermediate in bipolar disorder, and least in major depressive disorder. Given that working memory depends, in part, on neural circuitry that includes pyramidal cells in layer 3 (L3) and layer 5 (L5) of the dorsolateral prefrontal cortex (DLPFC), we sought to determine if transcriptome alterations in these neurons were shared or distinctive for each diagnosis.

Methods: Pools of L3 and L5 pyramidal cells in the DLPFC were individually captured by laser microdissection from 19 matched tetrads of unaffected comparison subjects and subjects with SZ, bipolar disorder, and major depressive disorder, and the messenger RNA was subjected to transcriptome profiling by microarray.

Results: In DLPFC L3 and L5 pyramidal cells, transcriptome alterations were numerous in subjects with SZ, but rare in subjects with bipolar disorder and major depressive disorder. The leading molecular pathways altered in subjects with SZ involved mitochondrial energy production and the regulation of protein translation. In addition, we did not find any significant transcriptome signatures related to psychosis or suicide.

Conclusions: In concert, these findings suggest that molecular alterations in DLPFC L3 and L5 pyramidal cells might be characteristic of the disease processes operative in individuals diagnosed with SZ and thus might contribute to the circuitry alterations underlying cognitive dysfunction in individuals with SZ.

Keywords: Bipolar disorder; Major depression; Microarray; Prefrontal cortex; Pyramidal neurons; Schizophrenia.

MeSH terms

  • Adult
  • Bipolar Disorder / diagnosis*
  • Depressive Disorder, Major / diagnosis*
  • Female
  • Gene Expression Profiling
  • Humans
  • Laser Capture Microdissection
  • Male
  • Microarray Analysis
  • Middle Aged
  • Prefrontal Cortex / pathology*
  • Pyramidal Cells / metabolism*
  • RNA, Messenger / metabolism
  • Reproducibility of Results
  • Schizophrenia / diagnosis*
  • Schizophrenia / pathology
  • Severity of Illness Index
  • Signal Transduction / physiology
  • Transcriptome / physiology*

Substances

  • RNA, Messenger