Suppressing cAMP response element-binding protein transcription shortens the duration of status epilepticus and decreases the number of spontaneous seizures in the pilocarpine model of epilepsy.

Abstract

OBJECTIVE:

Current epilepsy therapies directed at altering the function of neurotransmitter receptors or ion channels, or release of synaptic vesicles fail to prevent seizures in approximately 30% of patients. A better understanding of the molecular mechanism underlying epilepsy is needed to provide new therapeutic targets. The activity of cyclic AMP (cAMP) response element-binding protein (CREB), a major transcription factor promoting CRE-mediated transcription, increases following a prolonged seizure called status epilepticus. It is also increased in the seizure focus of patients with medically intractable focal epilepsy. Herein we explored the effect of acute suppression of CREB activity on status epilepticus and spontaneous seizures in a chronic epilepsy model.

METHODS:

Pilocarpine chemoconvulsant was used to induce status epilepticus. To suppress CREB activity, a transgenic mouse line expressing an inducible dominant negative mutant of CREB (CREB(IR) ) with a serine to alanine 133 substitution was used. Status epilepticus and spontaneous seizures of transgenic and wild-type mice were analyzed using video-electroencephalography (EEG) to assess the effect of CREB suppression on seizures.

RESULTS:

Our findings indicate that activation of CREB(IR) shortens the duration of status epilepticus. The frequency of spontaneous seizures decreased in mice with chronic epilepsy during CREB(IR) induction; however, the duration of the spontaneous seizures was unchanged. Of interest, we found significantly reduced levels of phospho-CREB Ser133 upon activation of CREB(IR) , supporting prior work suggesting that binding to the CRE site is important for CREB phosphorylation.

SIGNIFICANCE:

Our results suggest that CRE transcription supports seizure activity both during status epilepticus and in spontaneous seizures. Thus, blocking of CRE transcription is a novel target for the treatment of epilepsy.

• Authors: Xinjian Zhu, Deepti Dubey, Camilo Bermudez, Brenda E Porter
• Journal: Epilepsia (Epilepsia) Vol. 56 Issue 12 Pg. 1870-8 (Dec 2015) ISSN: 1528-1167 [Electronic] United States
• PMID: 26419901 (Publication Type: Journal Article, Research Support, N.I.H., Extramural)
• Copyright: Wiley Periodicals, Inc. © 2015 International League Against Epilepsy.

Chemical References

• Convulsants
• Pilocarpine
• CREB-Binding Protein
• Crebbp protein, mouse

Topics

• Animals
• Brain Chemistry
• CREB-Binding Protein (analysis, antagonists & inhibitors)
• Convulsants (pharmacology)
• Disease Models, Animal
• Female
• Immunoblotting
• Male
• Mice
• Mice, Inbred C3H
• Mice, Inbred C57BL
• Mice, Transgenic
• Phosphorylation
• Pilocarpine (pharmacology)
• Real-Time Polymerase Chain Reaction
• Seizures (chemically induced, physiopathology)
• Status Epilepticus (chemically induced, physiopathology)