New differentially expressed genes and differential DNA methylation underlying refractory epilepsy

// Xi Liu 1, * , Shu Ou 1, * , Tao Xu 1 , Shiyong Liu 2 , Jinxian Yuan 1 , Hao Huang 3 , Lu Qin 1 , Hui Yang 2 , Lifen Chen 1 , Xinjie Tan 1 , Yangmei Chen 1 1 Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Yuzhong District, Chongqing, 400010, China 2 Epilepsy Center of PLA, Department of Neurosurgery, Xinqiao Hospital, The Third Military Medical University, Shapingba District, Chongqing, 400037, China 3 Department of Neurology, Affiliated Hospital of Zunyi Medical College, Zunyi, 563003, China * These authors have contributed equally to this work Correspondence to: Xinjie Tan, email: xinjietan2009@yahoo.com Yangmei Chen, email: cq_neurologist@163.com Keywords: refractory epilepsy, human, epigenetics, DNA methylation, gene expression Received: September 28, 2016      Accepted: November 08, 2016      Published: November 26, 2016 ABSTRACT Epigenetics underlying refractory epilepsy is poorly understood, especially in patients without distinctive genetic alterations. DNA methylation may affect gene expression in epilepsy without affecting DNA sequences. Herein, we analyzed genome-wide DNA methylation and gene expression in brain tissues of 10 patients with refractory epilepsy using methylated DNA immunoprecipitation linked with sequencing and mRNA Sequencing. Diverse distribution of differentially methylated genes was found in X chromosome, while differentially methylated genes appeared rarely in Y chromosome. 62 differentially expressed genes, such as MMP19, AZGP1, DES, and LGR6 were correlated with refractory epilepsy for the first time. Although general trends of differentially enriched gene ontology terms and Kyoto Encyclopedia of Genes and Genome pathways in this study are consistent with previous researches, differences also exist in many specific gene ontology terms and Kyoto Encyclopedia of Genes and Genome pathways. These findings provide a new genome-wide profiling of DNA methylation and gene expression in brain tissues of patients with refractory epilepsy, which may provide a basis for further study on the etiology and mechanisms of refractory epilepsy.