Effect of gap junction protein Cx43 inhibitor on cognitive function and its possible mechanism in epileptic rats
10.3760/cma.j.cn115354-20210927-00633
- VernacularTitle:缝隙连接蛋白Cx43抑制剂对癫痫大鼠认知功能的影响及其机制研究
- Author:
Shi YAN
1
;
Aowen WANG
;
Xian HAN
;
Yifu SHU
;
Junchao LI
;
Hong SHEN
Author Information
1. 哈尔滨医科大学附属第一医院神经外科，哈尔滨 150001
- Keywords:
Gap junction protein Cx43;
Autophagy;
Cognitive function;
Temporal lobe epilepsy
- From:
Chinese Journal of Neuromedicine
2022;21(6):573-579
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the effect of gap junction protein Cx43 inhibitor carbenoxolone (CBX) on cognitive function and its possible mechanism in epileptic rats.Methods:One hundred and twenty Wistar rats were randomly divided into sham-operated group, epilepsy group, epilepsy+solvent group, and epilepsy+CBX group ( n=30). The models of temporal lobe epilepsy in the later three groups were prepared by injection of kainic acid in the hippocampus. Intraperitoneal injection of CBX (20 mg/kg) or equal amount of normal saline were given to the rats in the epilepsy+CBX group and epilepsy+solvent group 30 min before modeling. Western blotting was used to detect the protein expressions of phosphorylated (p)-Cx43 and microtubule associated protein light chain 3 (LC3) in the hippocampus 6, 12, and 24 h after modeling; the protein localization of p-Cx43 and LC3 in the hippocampus and optical density of their positive cells were detected by immunohistochemistry 24 h after modeling; the learning and memory abilities of rats were tested by Morris water maze experiment 30 d after modeling. Results:Western blotting results showed that as compared with those in the sham-operated group, p-CX43 and LC3 protein expressions in the hippocampal CA3 regions of epilepsy group and epilepsy+solvent group were significantly increased at 6, 12 and 24 h after modeling ( P<0.05); as compared with the epilepsy group and epilepsy+solvent group, the epilepsy+CBX group had statistically decreased p-CX43 and LC3 protein expressions in the hippocampal CA3 regions at each time point ( P<0.05). Immunohistochemical staining showed that p-CX43 was localized at the cell membrane and cytoplasm of hippocampal astrocytes; LC3 was located at the cytoplasm of hippocampal neurons. As compared with those in the sham-operated group, the optical density values of p-CX43 and LC3 positive cells in hippocampal CA3 regions of epilepsy group and epilepsy+solvent group were increased ( P<0.05). As compared with those in the epilepsy group and the epilepsy+solvent group, the optical density values of p-CX43 and LC3 positive cells in the hippocampal CA3 regions of the epilepsy+CBX group were significantly decreased ( P<0.05). Morris water maze test results showed that as compared with that in the sham-operated group, the escape latency in the epilepsy group and epilepsy+solvent group was significantly prolonged ( P<0.05); as compared with that in the epilepsy group and epilepsy+solvent group, the latency in the epilepsy+CBX group was significantly shortened ( P<0.05). Conclusion:CBX can weaken the neuronal autophagy and reduce the damage to cognitive function by inhibiting the p-Cx43 protein expression in the astrocytes of the hippocampal CA3 regions.
