Circulating miR‐146a and miR‐134 in predicting drug‐resistant epilepsy in patients with focal impaired awareness seizures

Abstract

Epilepsia. 2020;61:959-970. | 959 wileyonlinelibrary.com/journal/epi Abstract Objective: Epilepsy is one of the most prevalent neurologic disorders, causing serious psychological problems and reducing quality of life. Although 20 different antiepileptic drugs (AEDs) have been approved by the US Food and Drug Administration (FDA), 30% of patients have drug-resistant epilepsy (DRE). Considering the role of miR-146a and miR-134 in neuroinflammation and dendritic functionality, respectively, the aim of this study was the clinical evaluation of circulating miR-146a and miR-134 as novel noninvasive molecular markers for the prognosis of refractory epilepsy. Methods: The study included 162 patients with focal impaired awareness seizures. Total RNA was extracted from serum samples spiked with synthetic cel-miR-39-3p for normalization purposes. First-strand complementary DNA (cDNA) synthesis was performed using microRNA-specific stem-loop primers, and hsa-miR-134/146a levels were quantified by quantitative polymerase chain reaction (qPCR). DRE was used as clinical end point event. Internal validation was performed by bootstrap analysis, and decision curve analysis was used to evaluate the clinical benefit on disease prognosis. Results: The circulating levels of both miR-134 and miR-146a were elevated in patients with drug-resistant seizures. The receiver-operating characteristic (ROC) curve and logistic regression analysis demonstrated that patients with increased circulating miR-134/146a levels are at significantly higher risk for developing DRE, independently of temporal lobe sclerosis, epilepsy duration, familial history, age at first seizure, age, body mass index (BMI), smoking behavior, and gender. Finally, decision curve analysis highlighted that the evaluation of circulating miR-134/146a led to superior clinical benefit for DRE prognosis and patients' risk stratification. Significance: Elevated serum miR-134/146a levels are associated with a higher risk for AED-resistant epilepsy and could constitute novel noninvasive molecular markers to improve disease early prognosis and support precision medicine. K E Y W O R D S antiepileptic drugs, circulating miRNAs, drug-resistant epilepsy, drug-resistant seizures, microRNA 960 | LEONTARITI ET AL.

MicroRNA Dysregulation in Epilepsy: From Pathogenetic Involvement to Diagnostic Biomarker and Therapeutic Agent Development

“…Multiple regression analysis showed that downregulated miR-301a-3p expression represents a potential biomarker for the diagnosis of drug-resistant epilepsy, with a sensitivity of 81.5% and specificity of 81.2% (Wang et al, 2015a). Leontariti et al (2020) demonstrated that miR-134 and miR-146a serum levels were elevated in patients with drug-resistant epilepsy. These levels represented a significantly higher risk of developing drug-resistant epilepsy.…”

Aberrant expression of miRNAs in epilepsy

“…For instance, miR-134 could differentiate patients with MTLE from controls with diagnostic power of 0.75 [57]. It could also predict development of drug-resistance with power of 0.61 [59]. Since studies in this regard are not ample, it is not possible to find the impact of sample size, variations in the methodology, or geographic origin of the cohorts studied on the obtained results.…”

MicroRNAs in the development of resistance to antiseizure drugs and their potential as biomarkers in pharmacoresistant epilepsy

“…On the other hand, there is a subgroup of studies that do not follow the correlation of miRNA profiles in brain tissue and serum and only focus on miRNA levels in blood, verifying the existing results from other teams. 65,[93][94][95][96][97] Nevertheless, levels of several miRNAs have been shown to be correlated in tissue and peripheral blood, namely miR-153, 75 miR-129-2-3p, 91 miR-4521, 92 miR-323a-5p, 90 and a case report from De Matteis on miR-301a-3p. 86 Moreover, mir-153 has been validated in serum by two independent teams as well.…”

“…However, miR-301a deregulation is not specific for TLE, as its upregulation has been associated with immune response and inflammation similarly to miR-146a. 98 Authors have predicted targets of miR-301a-3p in silico, including mitogen-activated protein kinase 1, myeloid differentiation primary response 88, retinoblastoma-like protein 1, TNF receptor associated 65 The level of miR-146a along with miR-134 was explored in Leontariti et al 96 in the serum of patients with DRE. Both miRNAs are central to the development of neurological conditions, as they are deeply involved in the regulation of neuroinflammation and synaptic plasticity.…”