title: Alteration of Scn3a expression is mediated via CpG methylation and MBD2 in mouse hippocampus during postnatal development and seizure condition.
abstract: Increased expression of sodium channel SCN3A, an embryonic-expressed gene, has been identified in epileptic tissues, which is believed to contribute to the development of epilepsy. However, the regulatory mechanism of SCN3A expression under epileptic condition is still unknown. Here we showed a high level of Scn3a mRNA expression in mouse embryonic hippocampus with gradually decreasing to a low level during the postnatal development and a methylation of a specific CpG site (-39C) in the Scn3a promoter was increased in hippocampus during postnatal development, corresponding to the downregulation of Scn3a expression. Furthermore, in vitro methylation and -39C>T mutation of the Scn3a promoter decreased the reporter gene expression, suggesting an important role of the -39C site in regulating gene expression. We then demonstrated that the sequence containing -39C was a MBD2-binding motif and the CpG methylation of the promoter region increased the capability of MBD2's binding to the motif. Knockdown of MBD2 in mouse N1E-115 cells led to the -39C methylation and the downregulation of Scn3a transcription by decreasing the Scn3a promoter activity. In the hippocampus of seizure mice, the expressions of Scn3a and Mbd2 were upregulated after 10-day KA treatment. At the same time point, the -39C site was demethylated and the capability of MBD2's binding to the Scn3a promoter motif was decreased. Taken together, these findings suggest that CpG methylation and MBD2 are involved in altering Scn3a expression during postnatal development and seizure condition.
authors.affiliation: Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Collaborative Innovation Center for Neurogenetics and Channelopathies, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China; Key laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, Guangzhou Medical University, Guangzhou, China.
authors.forename: Hai-Jun
authors.initials: HJ
authors.lastname: Li
authors.affiliation: Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Collaborative Innovation Center for Neurogenetics and Channelopathies, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Rui-Ping
authors.initials: RP
authors.lastname: Wan
authors.affiliation: Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Collaborative Innovation Center for Neurogenetics and Channelopathies, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Ling-Jia
authors.initials: LJ
authors.lastname: Tang
authors.affiliation: Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Collaborative Innovation Center for Neurogenetics and Channelopathies, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Shu-Jing
authors.initials: SJ
authors.lastname: Liu
authors.affiliation: Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Collaborative Innovation Center for Neurogenetics and Channelopathies, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Qi-Hua
authors.initials: QH
authors.lastname: Zhao
authors.affiliation: Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Collaborative Innovation Center for Neurogenetics and Channelopathies, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Mei-Mei
authors.initials: MM
authors.lastname: Gao
authors.affiliation: Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Collaborative Innovation Center for Neurogenetics and Channelopathies, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Yong-Hong
authors.initials: YH
authors.lastname: Yi
authors.affiliation: Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Collaborative Innovation Center for Neurogenetics and Channelopathies, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China.
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Liao
authors.affiliation: Key laboratory of Reproduction and Genetics of Guangdong Higher Education Institutes, Guangzhou Medical University, Guangzhou, China. Electronic address: xiaofangsun@hotmail.com.
authors.forename: Xiao-Fang
authors.initials: XF
authors.lastname: Sun
authors.affiliation: Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, Collaborative Innovation Center for Neurogenetics and Channelopathies, Institute of Neuroscience, The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, China. Electronic address: longyuesheng@gzhmu.edu.cn.
authors.forename: Yue-Sheng
authors.initials: YS
authors.lastname: Long
mesh_terms: D000818:Animals; D018899:CpG Islands / Q000235:genetics; D019175:DNA Methylation / Q000235:genetics; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D047108:Embryonic Development; D018507:Gene Expression Regulation, Developmental; D006624:Hippocampus / Q000254:growth & development* / Q000473:pathology; D006801:Humans; D051379:Mice; D062552:NAV1.3 Voltage-Gated Sodium Channel / Q000096:biosynthesis* / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics; D012640:Seizures / Q000235:genetics* / Q000473:pathology; D014158:Transcription, Genetic
chemical_list: D004268:DNA-Binding Proteins; C489326:Mbd2 protein, mouse; D062552:NAV1.3 Voltage-Gated Sodium Channel; D012333:RNA, Messenger; C515216:Scn3a protein, mouse
keywords: CpG methylation; MBD2; Promoter; Scn3a; Seizure