Expression pattern of glial fibrillary acidic protein, Beclin-1 and microtubule-associated protein 2 after subarachnoid hemorrhage in rats

Objective To investigate the expression of glial fibrillary acidic protein (GFAP),Beclin-1 and microtubule-associated protein 2 (MAP2) after subarachnoid hemorrhage (SAH) in rats,and explore the relationship between early brain injury and autophagy in the process of SAH.Methods A total of 40 adult male SD rats were randomly divided into sham group and SAH 6 h,24 h and 3 day groups.Rats were decapitated under anesthesia after SAH induction.The brains were immediately removed and separated into hemispheres and cerebellums.The water content of each brain sample was weighed.A total of 10 adult male SD rats were decapitated under anesthesia after 3 days of SAH induction.The expression of GFAP,Beclin-1 and MAP2 was observed by double-labeled immunofluorescent staining.Results Following SAH induction,water content of the hemispheres was globally elevated,which was 78.25％ at 6th h after induction,and the increase was most significant at the 3rd day (79.75％,P ＜ 0.05).There was no significant difference in water content of the cerebellums among the different time points.Double-labeled immunofluorescent staining of GFAP/Beclin-1 showed that autophagy was expressed predominantly in neurons.And double-labeled immunofluorescent staining of Beclin-1/MAP2 showed that autophagy was obviously activated in neurons,which coordinated with the edema of brain.Conclusion The brain of rats showed the performance of early brain injury after SAH,and the neurons of hemisphere had the sign of autophagy activation in early phase.Autophagy may play a key role in the process of early brain injury after SAH. Key words: Subarachnoid hemorrhage;  Autophagy;  Early brain injury;  Beclin-1 ;  Microtubule-associated protein 2