The regulation of neurons autophagy in the hippocampus by PI3K-mTOR signaling pathways in SAH rats / 西安交通大学学报(医学版)

ABSTRACT

Objective To explore the regulation of PI3K-mTOR signaling pathways on autophagy of hippocampus nerve cells after subarachnoid hemorrhage (SAH)in rats.Methods We randomly divided 72 male Sprague-Dawley rats into sham group,SAH model group and LY294002 group with 24 rats in each group.We established SAH model with the secondary injection of blood method while the sham group was not injected with blood.PI3K signaling pathways specific inhibitor LY294002 was injected with 500μmol per rat 30 minutes before modeling.After 6,24,72 and 144 h morphologic changes of hippocampus CA1 neural cells were observed by microscopy;the expression levels of PI3K,mTOR,Beclin-1 and LC3-Ⅱ were detected by immunohistochemical method.Results The density of survival neurons in the SAH group was significantly lower than that in the control group (P<0.05),PI3K-mTOR signaling pathways were activated obviously,and the expressions of Beclin 1 and LC3-Ⅱ were significantly higher than those in the control group (P<0.05 ).The number of survival neurons significantly decreased in the LY294002 group compared with the SAH group at each time point (P<0.05),PI3K-mTOR signaling pathways were suppressed.The expressions of Beclin-1 and LC3-Ⅱ were significantly lower than those in the SAH group (P<0.05).Conclusion PI3K-mTOR signaling pathways protect neurons by activating the autophagy of neurons after SAH.