Investigation Of The Relationship Between The Serum Exosome MiR-155 And Children With Epilepsy

BackgroundEpilepsy is one of the most common neurological diseases in children.According to the World Health Organization,with 2.4 million people being diagnosed with epilepsy each year in the world,of which about 2 / 3 are children.At present,diagnosis of epilepsy remains principally based on clinical history and examination.Electroencephalogram(EEG)recording and brain imaging,but the medical history provided by children and their families is generally not detailed enough,and the possibility of general EEG capturing epileptic discharge waves is low,unless continuous video Electroencephalogram(EEG)monitoring is performed.Brain imaging is negative in many epileptic patients,and these factors can lead to errors or delays in the diagnosis of epilepsy.Therefore,it is urgent to find an objective and accurate biomarker to diagnose epilepsy in children.The main types of biomarkers of relevance to epilepsy are electrophysiological,imaging and molecular.Among the different types,molecular biomarkers are particularly attractive since they offer the possibility of rapid,simple and inexpensive bedside tests.Many studies have shown that miRNA,as a new biomarker of brain diseases,is involved in the origin and progress of epilepsy.Exosomes,as a new way of cell-to-cell communication,not only transmit miRNA,but also penetrate the blood-brain barrier freely.With the protection of exosomal lipid bilayer,miRNA can be transported for a long time and over long distances without degradation by endogenous ribonuclease.In recent years,exosomal miRNA may serve as valuable biomarkers for the diagnosis of many central nervous system diseases,including Alzheimer's disease,and Parkinson's disease.Reading the relevant literatures,we choose the microRNA-155(miR-155)as the goal of this study,which was significantly upregulated in the serum of animal models of epilepsy and human with epilepsy.By extracting the exosomes from the serum of epileptic children and healthy children,the differential expression of miR-155 in serum exosome was compared between epileptic children and healthy children,so as to provide a potential biomarker for the diagnosis of epilepsy.ObjectiveTo compare the differential expression of serum exosome miR-155 between children with epilepsy and healthy children,and to explore the diagnostic value serum exosome miR-155 in children with epilepsy.MethodsFrom October 2017 to October 2018,30 children with epilepsy diagnosed for the first time in the first affiliated Hospital of Zhengzhou University are enrolled in the epilepsy group.And 30 healthy children,followed by age and sex,in the same hospital children aim for the physical examination will into the healthy control group.The exosomes in serum were extracted by ultracentrifugation,identified by transmission electron microscopy,Nanoparticle tracking analysis and Western Blot,and the purity of RNA was tested by Nanodrop.The expression of serum exosome miR-155,serum suspension of exosomes were detected by real-time quantitative PCR(Quantitative Real-time PCR.The difference of expression was statistically analyzed by SPSS24.0 software(P < 0.05).Then the working characteristic curve(ROC curve)of the subjects was made.the differentially expressed miR-155 was analyzed by ROC curve.To evaluate the possibility of serum exosome non-coding miR-155 in the diagnosis of epilepsy in children.Results1.The exosomes in serum were identified by transmission electron microscopy and Nanoparticle tracking analysis.microvesicles with diameter of 30-100 nm could be detected,and the expression of exosome marker proteins CD63 and CD9 could be detected by Western Blot.2.Compared with the healthy control group,the serum exosome miR-155 in the epilepsy group was significantly higher than that in the healthy control group,the difference was statistically significant(t=4.783,P<0.05).3.In epilepsy group,by comparing the expression of miR-155 in serum exosome and serum suspension of exosomes,serum exosome miR-155 was significantly higher than in the serum suspension of exosomes,the difference was statistically significant(P < 0.05).4.In epilepsy group,the area under the curve of serum exosome miR-155 was 0.811,the specificity was 70%,the sensitivity was 83.3%,and the truncation value was 1.49.Conclusions1.In this study,exosome can be successfully extracted from serum by ultracentrifugation.2.This study showed that the expression level of serum exosome miR-155 in epilepsy group was significantly higher than that in healthy control group.it could speculate that exosome miR-155 might be involved in the pathogenesis of epilepsy.3.This study suggests that miR-155 in serum exosome is higher than that in in the serum suspension of exosomes,and serum exosome miR-155 may be more valuable in the diagnosis of epilepsy.4.This study suggests that when the expression level of serum exosome miR-155 is greater than 1.49,it may be suffering from epilepsy.