L-carnitine Inhibits H 2 O 2 -induced SH-SY5Y Cell Injury By The Endoplasmic Reticulum Pathway

OBJECTIVE To copy hydrogen peroxide?H₂O₂?-induced oxidative damage Alzheimer's disease model in SH-SY5 Y cells,and explore the protective effect of L-carnitine in SH-SY5 Y cells via modulating endoplasmic reticulum apoptotic pathway.METHODS The cells were divided into groups randomly as below: control group,H₂O₂?400?mol·L-1?model group,L-carnitine pretreated group?50?100?200 ?mol·L-13 h pretreatment followed by H₂O₂ treatment?and 4-PBA pretreated group?5?mol·L-1 3h pretreatment followed by H₂O₂ treatment?.DNA ladder and Annexin V-FITC staining were preformed to identify the apoptosis in SH-SY5 Y cells.Generation of ROS was detected by 2',7'-Dichlorofluorescin diacetate?DCFH-DA?.RT-PCR was preformed to detect the transcription of GRP78.The expression of GRP78,CHOP and caspase-12 were determined by western-blot.RESULTS The cells were incubated with 400?mol·L-1H₂O₂ for 20 min to establish the oxidative damage model.Obvious DNA ladder was observed in H₂O₂ treated group and the ladders in L-carnitine pretreated groups were much indistinct.The result of annexin V FITC/PI staining showed that the apoptosis in the early stage was inhibited as well as in the late stage of apoptosis and necrosis in L-carnitine pretreated groups compared with the H₂O₂ treated group.The results of RT-PCR and western-blot indicated the transcription and expression of GRP78 were increased in the H₂O₂ treated group and decreased in the L-carnitine pretreated groups.Compared with the H₂O₂ treated group,the expression of CHOP and caspase-12 were much lower in the L-carnitine pretreated groups.The result of DCFH-DA probe indicated that ROS was over-generated after H₂O₂ treatment,and the L-carnitine pretreatment could obviously inhibit the ROS generation.4-PBA could yield a week inhibitory effect to the ROS generation induced by H₂O₂ treatment.CONCLUSION L-carnitine could inhibit H₂O₂ induced apoptosis in SH-SY5 Y cells by down-regulating of the transcription and expression of GRP78,and decreasing the expression of CHOP and caspase-12.The protective effect of L-carnitine was related to the inhibition of ROS generation in endoplasmic reticulum.