miR-155-5p and miR-674-3p presence in peripheral blood and white blood cells as potential early biomarkers of temporal lobe epilepsy

Epilepsy frequently develops as a result of a brain insult, for example, brain injury or stroke. Currently, no tools are allowing us to predict which trauma patients will eventually develop epilepsy. There is evidence that microRNA levels are altered in the blood, making them attractive candidates for peripheral biomarkers of epilepsy. We analyzed whole blood miRNA levels using a dual-platform approach and selected miR-155-5p and miR-674-3p as candidates for biomarkers of early changes in asymptomatic temporal lobe epilepsy. Additionally, we assessed white blood cell subpopulations containing miR-155-5p and miR-674-3p in control and stimulated animals, as well as in control and symptomatic or asymptomatic animals in the amygdala stimulation model. The first proposed putative early biomarker of epilepsy is the relative proportion of CD45RA⁺ B cells containing miR-155-5p and/or miR-674-3p. Others are an increased number of CD45RA⁺ B cells containing either miR-155-5p or both miR-155-5p and miR-674-3p, or a decreased number of CD161+ NK cells that do not contain either miR-155-5p or miR-674-3p. Additionally, we found that the decreased number of CD4⁺ T cells can. These putative biomarkers should be subjected to further studies in other epilepsy models and larger cohorts.