SPAK on Functional Remodeling of GABA Signal in Hippocampal Neurons In Mice with Drug-resistant Epilepsy

Yang Libai; Cai Xiaodong; Zhou Liemin; Niu Zhengping; Li Xinyi

doi:10.3969/j.issn.1672-1349.2017.23.011

Abstract：Objective To explore the possible mechanism of the remodeling of GABA signaling function in drug resistant epilepsy with pilocarpine-induced status epilepticus (PISE) mice.Methods The healthy male Balb/c mice (4-6 weeks) were used in the study.The animals were randomly divided into three groups:a PISE group,sham-control group,and blank-control group.Three main phases were observed following PISE:the acute stage,the subacute stage,and the chronic stage with spontaneous recurrent seizures,represented as day 1,day 14 and day 45,respectively,after PISE.Double labeling was used for investigating SPAK/NeuN co-expression in mice hippocampus.Western Blot were used for testing SPAK protein expressional level differences between groups in mice hippocampus.lntracellular chloride concentration [Cl-]i of mice hippocampus neurons was detected by N-(6-methoxyquinolyl) acetoethyl ester (MQAE).Co-immol/Lunoprecipitation were used to detect the interaction between SPAK and N KCC1 or KCC2.Resuits SPAK expressed and co-expressed with NKCC1 and KCC2 in the hippocampal neurons of mice.Significant increases in SPAK protein levels were detected during various stages of PISE in the PISE mice in comparison to levels in age-matched sham (control) and blank treatment (control) mice (P ＜0.05).While[Cl-]i of hippocampal neurons in the various stages PISE mice increased significantly (P ＜0.05).Using co-immol/Lunoprecipitation.The intensity of interaction between SPAK and NKCC1 and between SPAK and KCC2 increased markedly in the chronic stage.Conclusion SPAK is involved in remodeling of GABA signaling function in drug resistang epilepsy via adjusting [Cl-]i through interacting with NKCC1,and KCC2 in mouse hippocampus neurons.