GENE EXPRESSION PROFILING DURING SLEEP DEPRIVATION AND AFTER KAINATE-TRIGGERED EPILEPTOGENESIS IN ADULT RAT BRAIN
Abstract number :
2.121
Submission category :
Year :
2003
Submission ID :
3785
Source :
www.aesnet.org
Presentation date :
12/6/2003 12:00:00 AM
Published date :
Dec 1, 2003, 06:00 AM
Authors :
Walter J. Lukiw, Nicolas G. Bazan Louisiana State University Health Sciences Center, Neuroscience Center and Department of Ophthalmology, New Orleans, LA
Epileptoform seizures result from sleep deprivation (SLDP) in a substantial proportion of patients with epilepsy. These data suggest a continuum in brain neurophysiological mechanisms linking sleep deprivation to seizure onset. To further understand brain gene signaling pathways involved in seizure acquisition and proliferation we used a high density gene profiling approach in adult rat brain hippocampus to categorize the expression of genes involved (a) after 3 days of total SLDP and (b) after kainate- (KA)-induced epileptogenesis.
Total RNA was extracted and purified from controls and SLDP- or KA-treated animals using phenol-guanidine isothiocyanate reagents. Potential total RNA samples were screened for spectal purity and integrity using RNA LabChips (Caliper Technologies, Mountain View, CA) and a 2100 Bioanalyzer (Agilent Technologies, Palo Alto, CA). DNA array analysis was performed using RG U34A Genechips (Affymetrix, Santa Clara, CA). Elevated gene abundances were confirmed independently using RT-PCR. Gene expression data were analyzed using GeneSpring (Silicon Genetics, Redwood City, CA) and Microarray Data Mining Tool version 2.0 (Affymetrix) software.
Of 8801 gene expression levels profiled, we report common strong increases in the abundance of (1) polyubiquitin (Q63446) and endoplasmic reticulum protein 72 (ERSP72; P38659) RNA message, each encoding housekeeping gene products involved in cellular stress and catabolic responses and (2) marked induction of cyclooxygenase-2 (COX-2; Q63124) RNA message that encodes a neuron-specific rate-limiting enzyme which generates prostanoids from arachidonic acid and whose expression is regulated by physiological synaptic activity.
These results suggest that both SLDP- and KA-induced experimental epileptogenesis of rodent brain induces a robust and sustained cellular stress response in the hippocampal formation and that COX-2 and its diffusible prostanoid products may play a role in propagating excitatory signaling, activity-dependent plasticity and seizure development.
[Supported by: DARPA N65236-01-1-5435, NIH AG18031 and NINDS NS23002.]