Identification of serum miRNAs differentially expressed in human epilepsy at seizure onset and post-seizure

Abstract

MicroRNAs (miRNAs) function as potential novel biomarkers for disease detection due to their marked stability in the blood and the characteristics of their expression profile in several diseases. In the present study, microarray-based serum miRNA profiling was performed on serum obtained from three patients with epilepsy at diagnosis and from three healthy individuals as controls. This was followed by reverse transcription-quantitative polymerase chain reaction analysis in a separate cohort of 35 health volunteers and 90 patients with epilepsy. The correlations between miRNAs and clinical parameters were analyzed. The array results showed that 15 miRNAs were overexpressed and 10 miRNAs were underexpressed (>2-fold) in the patients with epilepsy. In addition, four miRNAs, including miR-30a, miR-378, miR-106b and miR-15a were found to be overexpressed in the serum of patients at seizure onset, compared with post-seizure. When the patients were at seizure onset, the expression of miR-30a was positively associated with seizure frequency. No significant differences were found between miR-30a and gender, age or number of years following diagnosis. The expression levels of miR-378, miR-106b and mir-15a were not associated with the clinical parameters in the patients with seizures. Calcium/calmodulin-dependent protein kinase type IV was a target of miR-30a, and its expression was increased following seizure and was negatively correlated with miR-30a in the patients with epilepsy. The present study provided the first evidence, to the best of our knowledge, that the expression levels of miR-378, miR-30a, miR-106b and miR-15a were enhanced in epileptic patients with seizures. miR-30a may be useful for prognostic prediction in epilepsy.