Stage and sub‐field associated microRNA changes in epilepsy

Abstract

Epilepsy is a neurological disease characterized by chronic, recurring seizures and affects about 50 million people worldwide. Of the two major cell groups in the hippocampus, CA1 pyramidal neurons are prone to excitotoxicity and degeneration while the granule cells of the dentate gyrus (DG) exhibit seizure resistance and neurogenesis during epilepsy. MicroRNAs(miRNAs) are small, non‐coding RNAs recognized as significant regulators of gene expression. While there are reports of miRNA changes in epilepsy, none of them have analyzed the differential miRNA expression in the DG and CA1 regions. In order to identify the changes in miRNA expression in both regions we performed a miRNA microarray of the DG and CA1 regions from pilocarpine‐induced epileptic mice at 3, 14 days and 2 months after induction of epilepsy.164 miRNAs in DG and 111 miRNAs in CA1 were differentially expressed as compared to control at all three time points (p<0.01). Of these, 79 miRNAs were common between DG and CA1, 85 were only in DG and 32 only in CA1. The expression of 5 randomly picked deregulated miRNAs was confirmed using qPCR. Using web‐based databases and a PCR array for mRNA expression we have identified 6 signal transduction pathways modulated by the deregulated miRNAs. These results provide an insight into the miRNA‐based differential regulation of signal transduction pathways in CA1 and DG regions during status epilepticus. Supported By BMRC grant ‐R.181.000–129‐305.