Dynamic Expression of MicroRNAs (183, 135a, 125b, 128, 30c and 27a) in the Rat Pilocarpine Model and Temporal Lobe Epilepsy Patients

Recently, microRNAs (miRNAs) are emerging as new regulators in the pathogenesis of temporal lobe epilepsy (TLE) and playing a major role in the inflammatory and immune processes. The aim of the present study was to evaluate the dynamic expression of brain-specific miR-183 and miR-135a, brain-enriched miR-125b and miR-128 and inflammation-related miR-30c and miR-27a. Status epilepticus evoked by pilocarpine administeration was used to induce epilepsy in rats. Quantitative polymerase chain reaction was performed on rat hippocampus 2 hours, 3 weeks and 2 months following pilocarpine-induced status epilepticus, representing the acute, latent, and chronic phases, respectively. Expression levels were also measured in hippocampus obtained from TLE patients and normal controls. In the rat model, miR-183, miR-135a and miR-125b were detected upregulated during the acute and chronic phases compared to controls, but not during the latent phase. miR-30c and miR-27a were upregulated in the acute and chronic phases of TLE, while in the latent phase miR-30c was downregulated and miR-27a was upregulated. On the other hand, miR-128 showed significantly downregulated in all phases of TLE development. In TLE patients, miR-183, miR- 135a, miR-125b, miR-30c and miR-27a were upregulated, whereas miR-128 was downregulated. Our study revealed upregulation of miR-183, miR-135a and miR-125b in the seizure-related phases and TLE patients, suggesting that all may provide a potential therapeutic approach for the treatment of TLE, whereas the dysregulation of miR-128, miR-30c and miR-27a may suggest different functions during the process of TLE development.