Cluster analysis of mRNA expression levels identifies multiple sequential patterns following focal cerebral ischemia

Turk Neurosurg. 2012;22(4):441-7. doi: 10.5137/1019-5149.JTN.5523-11.0.

Abstract

Aim: The purpose of this study is to detect gene expression patterns following focal cerebral ischemia.

Material and methods: 25 male Wistar rats were divided into control (n = 8) and ischemic (n = 17) groups. In the ischemic group, slowly progressing focal ischemia was simulated by two-vein occlusion with spreading depression (SD) a cortical microinjection of KCl induced. Ischemic tissue was removed at 2, 8, 24, or 72 h postischemia. Using semiquantitative reverse transcription polymerase chain reaction, we investigated mRNA expression levels of 13 representative genes related to cerebral ischemia. Cluster analysis of the gene expression levels was done.

Results: In the ischemic group, the expression levels of c-fos, cyclin D1, and COX-2 were significantly higher at 2 h postischemia, and those of bcl-2, bcl-xL, and HO-1 at 72 h. Based on the cluster analysis, we statistically divided examined genes into three groups: group A, early expression (COX-2, c-fos, and bcl-2); group B, s expression (c-jun, SOD-1, bad, p53, SOD-2, bcl-xL, and bax); and group C, late expression (cyclin D1, c-myc, and HO-1).

Conclusion: We statistically classified the genes into three groups after focal ischemia. The genes of the early- and late-expression groups can be possible therapeutic targets for the treatment of cerebral ischemia.

MeSH terms

  • Animals
  • Cerebral Cortex / blood supply
  • Cerebral Veins / physiology
  • Cluster Analysis
  • Cortical Spreading Depression
  • Electric Impedance
  • Intracranial Thrombosis / metabolism
  • Ischemic Attack, Transient / metabolism*
  • Male
  • Nerve Tissue Proteins / biosynthesis*
  • Nerve Tissue Proteins / genetics
  • Photochemistry
  • Potassium Chloride / pharmacology
  • RNA, Messenger / biosynthesis*
  • RNA, Messenger / genetics*
  • Rats
  • Rats, Wistar
  • Real-Time Polymerase Chain Reaction
  • Transcription, Genetic

Substances

  • Nerve Tissue Proteins
  • RNA, Messenger
  • Potassium Chloride