Effect of cannabinoid receptor type 2 on the expression of autophagy-related proteins LC3 and Beclin-1 in the hippocampal CA1 region of rats with status epilepticus / 中国小儿急救医学

ABSTRACT

Objective To explore effect of cannabinoid receptor type 2(CB2R)on the expression of autophagy-related proteins LC3 and Beclin-1 in the hippocampal CA1 region of rats with status epilepticus ( SE). Methods SE model was established by treating lithium chloride-pilocarpine intraperitoneally injection in Sprague-Dawley(SD) rats. All the rats were randomly divided into four groups including Control group, Epilepsy group,Epilepsy + JWH-133 group and Epilepsy + AM630 group. JWH-133, AM630, and DMSO were injected 60 min before pilocarpine injection by intracerebroventricular injection ( Control group and Epilepsy group with DMSO,Epilepsy+JWH-133 group with JWH-133 and Epilepsy+AM630 group with AM630). At 24 h after SE,the epileptic symptoms were observed. HE staining was performed to observe the number changes of neurons in the hippocampal CA1 region. The spatiotemporal expressions of LC3 and Beclin-1 in the hippocampal CA1 region were observed using Double-label immunofluorescence and Western blot. Results Epileptic symptoms showed that rats in the control group had no obvious epileptic seizures. Those in Epilepsy group presented seizures about (13. 50 ± 0. 61)min after treated with pilocarpine and racine scale was (4. 33 ± 0. 47) scores. The latency period in Epilepsy+JWH-133 group was(19. 33 ± 0. 42) min and longer than that in the Epilepsy group(P<0. 05);Racine scale in Epilepsy+JWH-133 group was 3. 33 ± 0. 59 and less than the Epilepsy group( P<0. 05). The opposite effect was observed in Epilepsy+AM630 group. HE staining showed that compared with the Epilepsy group,the number of the hippocampal CA1 neu-rons increased in Epilepsy+JWH-133 group and decreased in Epilepsy+AM630 group. Immunofluorescence and Western blot showed that LC3 and Beclin-1 were mainly expressed in neurons,and the expression of LC3 and Beclin-1 in Epilepsy group were up-regulated dynamically than that in the control group at 24 h after SE (P<0. 05). Furthermore compared with the Epilepsy group,the expression of LC3 and Beclin-1 in Epilepsy+JWH-133 group were higher but lowered in Epilepsy+AM630 group. Conclusion We demonstrate that CB2R may play a role in autophagy of the hippocampal neurons at the early stage of pilocarpine-induced SE and hinted CB2R may become a treatment target for epilepsy.