Correlation of transcriptome profile with electrical activity in temporal lobe epilepsy

Neurobiol Dis. 2006 May;22(2):374-87. doi: 10.1016/j.nbd.2005.12.012. Epub 2006 Feb 9.

Abstract

The biology underlying epileptic brain activity in humans is not well understood and likely depends on changes in gene expression. We performed a microarray transcriptome profiling of 12 anterolateral temporal cortical samples originating from five individuals who suffered with temporal lobe epilepsy for at least 10 years. Prior to partial lobectomy, intraoperative electrocorticography was performed on the cortical surface of each patient. These recordings showed characteristic differences in frequency and amplitude that were defined as "spiking" (abnormal) or "non-spiking" (normal). Between the transcriptome of the two sample groups, transferrin (TF) was the most differentially expressed gene. Furthermore, gene expression profiling also revealed a downregulation of multiple GABA system-related genes (GABRA5, GABRB3, ABAT) in the spiking samples and an upregulation of oligodendrocyte and lipid metabolism transcripts (MOG, CA2, CNP, SCD, PLP1, FA2H, ABCA2). In addition, several transcripts related to the classical MAPK cascade showed expression level alterations between the spiking and non-spiking samples (G3BP2, MAPK1, PRKAR1A, and MAP4K4). Out of 12 genes chosen for verification by RT qPCR, 9 showed significant expression changes in the microarray-predicted direction. Furthermore, the microarray and qPCR data were highly correlated (r = 0.98; P < 0.001). We conclude that abnormal electrical brain activity in the spiking samples is strongly correlated with gene expression changes and we speculate that some of the observed transcriptome changes may be directly involved in the induction or prevention of the ictal events seen in epilepsy.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Action Potentials / genetics
  • Adult
  • Down-Regulation / genetics
  • Electroencephalography
  • Epilepsy, Temporal Lobe / genetics*
  • Epilepsy, Temporal Lobe / metabolism
  • Epilepsy, Temporal Lobe / physiopathology*
  • Female
  • Gene Expression Profiling
  • Gene Expression Regulation / genetics*
  • Humans
  • MAP Kinase Signaling System / genetics
  • Male
  • Myelin Proteins / genetics
  • Myelin Proteins / metabolism
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism
  • Oligonucleotide Array Sequence Analysis
  • Temporal Lobe / metabolism*
  • Temporal Lobe / pathology
  • Temporal Lobe / physiopathology*
  • Up-Regulation / genetics
  • gamma-Aminobutyric Acid / metabolism

Substances

  • Myelin Proteins
  • Nerve Tissue Proteins
  • gamma-Aminobutyric Acid