ABSTRACT
AIM:To observe the effect of rapamycin (Rapa) on human neuroblastoma SH-SY5Y cell injury induced by oxygen-glucose deprivation (OGD), and to explore the role of autophagy in this process .METHODS: The SH-SY5Y cells were randomly divided into 4 groups:normal control group:the cells were cultured without OGD treatment;Rapa group:the cells were pretreated with Rapa for 1 h;OGD group:the culture medium was replaced by glucose-free me-dium and the cells were transferred to a humidified incubation chamber flushed by a gas mixture of 1%O2 , 94%N2 and 5% CO2 for 12 h; Rapa+OGD group: the cultured cells were treated with Rapa for 1 h, and then were given the same treatments as those in OGD group .The cell viability was assessed by MTT assay .The degree of the cell damage was evalu-ated by determining the leakage of lactate dehydrogenase ( LDH) .The enzyme activity of caspase-3 was detected .TUNEL staining were used to detect the variation of cell apoptosis .The protein levels of apoptosis-related proteins Bax and Bcl-2, autophagy-related protein beclin-1 and autophagy marker protein LC 3B were determined by Western blot .RESULTS:Compared with OGD group, the viability of the SH-SY5Y cells was significantly increased, and the activity of caspase-3 was significantly reduced in Rapa +OGD group (P<0.05).The SH-SY5Y cell injury was apparent after OGD with a great in-crease in the apoptotic rate (P<0.05).Compared with OGD group, the apoptotic rate significantly decreased in Rapa +OGD group (P<0.05).Compared with control group, the protein level of Bcl-2 was significantly decreased (P<0.05) and the protein level of Bax was significantly increased in OGD group .Compared with OGD group , the levels of Bcl-2, be-clin-1 and LC3B-Ⅱwere significantly increased and the protein level of Bax was significantly increased in Rapa +OGD group (P<0.05).CONCLUSION: Rapamycin has a protective effect on in vitro cultured SH-SY5Y cells injured by OGD.The mechanism may be related to the promotion of autophagy .