Changes of autophagy-related genes in the brains of the rats in the developmental stage with epilepsy / 中华实用儿科临床杂志

ABSTRACT

Objective To explore the changes of Beclin-1,P62/SQSTM1,microtubule-associated protein 1 light chain 3 (LC3)and unc-51 like autophagy activating kinase 1 (ULK-1)in the brains of the rats in the deve-lopmental stage with epilepsy. Methods Seventy-two male Sprague Dawley (SD)rats aged 21 days were randomly divided into the control group and the epilepsy group. The rats in 2 groups were randomly subdivided into 4 groups according to the time intervals (3 h,6 h,12 h and 48 h),respectively,with 9 rats in each group. The rats in the epilep-sy group were injected with kainic acid (12 mg/kg)to induce epilepsy,and the rats in the control group were injected with equal volume of saline. The rats in 2 groups were anaesthetized and sacrificed. Then,the brain tissues of the rats were quickly removed according to the time intervals. The brain damages were determined by adopting Nissl staining method. The apoptotic cells were detected by Terminal - deoxynucleoitidyl transferase mediated nick end labeling (TUNEL)assays. The expressions of Beclin-1,P62/SQSTM1,LC3 and ULK-1 mRNA levels in cortex were mea-sured by using real-time quantitative polymerase chain reaction (qPCR)analysis. Results Nissl staining indicated that many neurons were damaged performing vague outline,irregularly aligned,pyknotic nuclei and shrunken somata in the epilepsy 48 h group. In addition,there was a huge loss of neurons in cortex in the epilepsy 48 h group [(82 ± 8)num-bers],compared with the control group [(122 ± 8)numbers],and the difference was statistically significant (F＝3. 768, P＝0. 01). The apoptotic cells tremendously increased in the epilepsy 48 h group [(13 ± 7)numbers],compared with the control group [(2 ± 1)numbers]by TUNEL analysis,and the diffe-rence was statistically significant (t＝ -3. 821, P＝0. 003). qPCR showed the mRNA levels of Beclin-1,P62/SQSTM1,LC3 and ULK-1 were upregulated in the epi-lepsy 12 h group (1. 70 ± 0. 75,1. 75 ± 0. 77,1. 52 ± 0. 43,7. 48 ± 6. 12)and the epilepsy 48 h group (1. 63 ± 0. 43, 1. 48 ± 0. 74,1. 74 ± 0. 55,7. 69 ± 5. 65),compared with the control group (1. 00,1. 00,1. 00,1. 00),and the differences were statistically significant (F＝2. 820,3. 452,5. 811,5. 002,all P＜0. 05). Conclusion The autophagy activates be-fore apoptosis occurs,and autophagy-related genes probably are involved in epilepsy-induced brain damage.