Expression and significance of signaling pathway of miR-134/CREB/pCREB in patients with epilepsy and in epileptic rats / 中国实验动物学报

ABSTRACT

Objective To investigate the expression of microRNA-134 ( miR-134 ) , CREB and pCREB in the temporal lobe tissue of patients and epileptic rats and to explore their roles in pathogenesis of epilepsy.Methods Tempo-ral lobe tissue samples of 14 patients with refractory epilepsy and 10 non-epileptic patients, and hippocampus and brain tis-sue samples of 42 rats were used in this study.Forty-two healthy adult male Sprague-Dawley rats were randomly divided in-to 6 epilepsy groups (24 h, 72 h, 7 d, 14 d, 30 d, and 60 d after kindling epilepsy) and a normal control group (n=6 for all groups) .The rat model of epilepsy was generated by intraperitoneal injection of 127 mg/kg lithium chloride and 16-20 h later, 35 mg/kg pilocarpine.In the temporal lobe tissue of patients and hippocampal tissue of rats, the expression level of miR-134 was detected by real-time polymerase chain reaction.The expression levels of CREB and pCREB were de-termined by Western blot, and CREB and pCREB localization was assessed by immunohistochemistry.Results Compared with the control rats, the expression of miR-134 was significantly decreased in the temporal lobe tissue of experimental rats at 72 h,7 d,14 d, 60 d after kindling (P＜0.05),and no significant change at 24 h and 30 d after kindling (P>0.05). Expression of miR-134 in patients with refractory epilepsy was significantly lower than that of the controls ( P＜0.05 ) , while up-regulation of CREB expression was at the same time points (P＜0.05).Up-regulation of pCREB expression was at all the time points after kindling (P＜0.05).CREB and p-CREB expressions were seen in the nuclei of neurons, and significantly higher in patients with refractory epilepsy and epileptic rats.Conclusions The expression of miR-134 is sig-nificantly decreased and that of CREB and pCREB was significantly increased in the temporal lobe tissue of patients with re-fractory epilepsy and the hippocampal tissue of epileptic rats.These findings indicate that the signaling pathway of miR-134/CREB/pCREB may play an important role in the pathogenesis of epilepsy.