The Expression And Role Of Cx43 And Cx36 In Epilepsy

Objective:Epilepsy is a kind of repetitive and transient nervous system disorder caused by abnormal discharge of neurons.It brings great burden to individuals, families and society.The mechanism of epilepsy is still unclear.Gap junction is the channel between cells, which carries a lot of information exchange. Gap junction was considered to play a very important role in the process of the occurrence and development of epilepsy. Cx36, Cx43 as gap junction family members, also plays an irreplaceable role in epilepsy.In our study, we set up acute epilepsy rat model, observed and recorded the change of their behavior and detected the changed expression of Cx43, Cx36,Caspase-3, Bcl-2 and Bax in rats brain hippocampus and cortex to investigate the relationship in gap junction,apoptosis and epilepsy for finding possible targets of guiding clinical treatment of epilepsy.Method:Acute epilepsy model of rat was induced by intraperitoneal injection of PTZ, the rats were randomly divided into control and 2h, 6h, 12 h, 1d, 3d after epilepsy group.The control group was injected with the same amount of normal 0.9% saline, the experimental group was given intraperitoneal injection of PTZ. The behavior changes of rats in each group were observed and we observe dynamic changed expression of Cx43, Cx36, Caspase-3, Bcl-2 and Bax in the hippocampus and cortex by HE,immunohistochemistry, RT-PCR and Western Blot.Results:1. The immunohistochemistry staining showed that Cx36 distributed mainly in rat cortex and hippocampus(especially in CA1 and CA3). Compared with the control group, the expression of Cx36 increased from 2h, 12 h, 1 d slightly reduced at 12 h and1d, increased again at 3d.The expression of Cx43 significantly increased in 2h,maintained this level to 3d.2. The results of Western blot showed that the changes of Cx43 and Cx36 were consistent with the results of immunohistochemistry staining. In addition, the expression of Caspase-3 increased from 2h, and reached the peak in 12h-1d. The ratio of Bax/Bcl-2 also increased significantly after 2h.3. PCR results show that the expression of Cx43, Cx36, Caspase-3 and Bax/Bcl-2ratio is also significantly increased in the model group after 2h.4. The Cx43 and Cx36 m RNA of SH-SY5 Y with RA had no significant difference after Mg2+ free treatment.Conclusions:1. The changes of the expression of Cx43 and Cx36 were the most obvious in hippocampus CA1 and CA3, Cx43 and Cx36 may be involved in the process of hippocampal injury induced by PTZ in acute epilepsy.2. Neurons in the cortex and hippocampus of PTZ induced acute epilepsy rats may induce apoptosis through the mitochondrial pathway.