Long-term increase of Sp-1 transcription factors in the hippocampus after kainic acid treatment

Brain Res Mol Brain Res. 1999 May 21;69(1):144-8. doi: 10.1016/s0169-328x(99)00099-6.


Systemic administration of kainic acid (KA), a glutamate receptor agonist, causes robust seizures and has been used as an excellent rodent model for human temporal lobe epilepsy. Recently, we have demonstrated that a single injection of KA increases the steady-state levels of proenkephalin (PENK) mRNA in the rat hippocampus for at least one year. However, the molecular mechanisms underlying this long-term increase in PENK mRNA levels have not been clearly defined. To determine the possible involvement of the Sp-1 transcription factors in this regulation, electrophoresis mobility-shift assays were used to study the expression of Sp-1 factors in the hippocampus after KA treatment. The results showed that there are long-lasting increases in Sp-1 DNA-binding activity. The Sp-1 DNA-binding complexes were only competed by the non-radioactive Sp-1 element and not by ENKCRE2, AP-1 or CRE elements, indicating the specificity of Sp-1 DNA-binding activity. Since the expression of Sp-1 parallels the time course of long-lasting increase in the expression of PENK mRNA and mossy fiber sprouting after KA treatment, we hypothesize that the increase in Sp-1 activity may be associated with the long-term changes in the plasticity of hippocampal function after KA-induced seizures.

MeSH terms

  • Animals
  • Antibodies
  • Brain Chemistry / genetics
  • DNA Primers
  • Disease Models, Animal
  • Epilepsy, Temporal Lobe / physiopathology
  • Excitatory Amino Acid Agonists / pharmacology*
  • Gene Expression / drug effects
  • Kainic Acid / pharmacology*
  • Male
  • Mossy Fibers, Hippocampal / chemistry
  • Mossy Fibers, Hippocampal / drug effects*
  • Mossy Fibers, Hippocampal / physiology
  • Nerve Degeneration / chemically induced
  • Nerve Degeneration / physiopathology
  • Protein Binding / physiology
  • Rats
  • Rats, Inbred F344
  • Sp1 Transcription Factor / genetics*
  • Sp1 Transcription Factor / immunology
  • Sp1 Transcription Factor / metabolism*


  • Antibodies
  • DNA Primers
  • Excitatory Amino Acid Agonists
  • Sp1 Transcription Factor
  • Kainic Acid