The mechanism of oxygen free radical/JNK signaling pathway on neuronal autophagy after subarachnoid hemorrhage in rats
10.16571/j.cnki.1008-8199.2017.09.007
- VernacularTitle:氧自由基/JNK信号通路在蛛网膜下腔出血大鼠神经细胞自噬中的作用机制
- Author:
Shouming CAO
;
Xin YAN
;
Jianmin LI
- Keywords:
Subarachnoid hemorrhage;
Oxygen free radical;
c-Jun N-terminal kinase;
Autophagy;
Rat
- From:
Journal of Medical Postgraduates
2017;30(9):926-931
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate the mechanisms of oxygen free radical/JNK signaling pathway on neuronal autophagy after subarachnoid hemorrhage(SAH) in rats.Methods 160 male Sprague-Dawley rats were randomly divided into four groups: sham group, SAH model group, low dose Edaravone group and high dose Edaravone group.The SAH model was established by autologous blood injection into cisterna magna twice, while the rats in the sham group were injected with isotonic saline(0.3mL/time).The high dose of edaravone group and low dose of edaravone group were given 5mg/kg or 10mg/kg of edaravone, respectively, once daily with tail intravenous injection after the models were established.The morphological changes of hippocampus neural cells were detected by light microscope.The malondialdehyde (MDA) level in brain tissue was determined with thiobarbituric acid.The changes of phosphorylated JNK and autophagic biomarkers (Beclin-1 and LC3-II)were detected by immunohistochemical method.The expressions of JNK mRNA,Beclin-1 mRNA and LC3 mRNA in hippocampus was detected by Real time-quantitative PCR.Results The necrotic nerve cells were seen in the hippocampus of SAH group in terms of nuclear dissolution, nuclear fragmentation or nuclear disappearance.Compared with Sham group, the level of MDA and the number of dead neurons, the expression of JNK mRNA, Beclin-1 mRNA and LC3-Ⅱ mRNA were increased in the SAH group (P<0.05).The survival rate of nerve cells in the SAH group was lower than that in the sham group.The immunoreactivity of phosphorylated JNK 、Beclin-1 and LC3-Ⅱ in the SAH group was enhanced than that in the sham group.However the damage of the morphological structure of nerve cells was relatively decreased in both doses groups.Compared with SAH group, the level of MDA and the expression of JNK mRNA in low dose Edaravone group and high dose Edaravone group were decreased.The expression of Beclin-1 mRNA and LC-3 mRNA was higher (P<0.05).Furthermore, the survival rates of nerve cells in both dosesgroups were higher than that in the SAH group (P<0.05).Meanwhile, the immunoreactivity of phosphorylated JNK in both doses groups was weakened than that in the SAH group.The mRNA expression of Beclin-1 and LC3-Ⅱ was increased(P<0.05).Conclusion Oxygen free radical played an important role in process of neuronloss by activating the JNK signaling pathway to regulate Beclin-1 and LC3-Ⅱ expression.
