Protective effect of Sestrin2 on apoptosis of dendritic cells induced by high mobility group box-1 protein / 解放军医学杂志

ABSTRACT

Objective To investigate the potential role of Sestrin2 (SESN2) in regulating the apoptosis of dendritic cells (DCs) induced by high mobility group box-1 protein (HMGB1).Methods DCs (the murine DC cell line DC2.4) were cultured with or without HMGB1 stimulation (cultured with 10ng/ml HMGB1 for 8,24 and 48 hours,or cultured with HMGB1 for 48 hours at different concentrations of 1,10 and 100ng/ml,respectively,n=4).The protein level of SESN2,cleaved-caspase-3 and Bcl-2 were analyzed with Western blotting.Localization of SESN2 in cells was observed under confocal laser microscope (LSCM).Cell apoptosis was analyzed with flow cytometry.In addition,DC2.4 cells were transfected with lentivirus containing SESN2 LV-RNA,SESN2 siRNA sequence expressing plasmids or blank vector (NC,NS,n=4).These cells were then stimulated with HMGB1 (100ng/ml)for 48 hours,and the apoptosis was accessed as mentioned above.Results Compared with the control group,the expression of SESN2 was obviously up-regulated after HMGB1 (10ng/ml) stimulation for 24 and 48 hours (P＜0.05).In a dose-dependent response,the expression of SESN2 was markedly enhanced in treatment with 1,10,100ng/ml HMGB1 for 48 hours (P＜0.05).Compared with the control group (7.35％ ± 1.33％),the percentage of apoptosis was significantly increased with 10,100ng/ml HMGB1 for 48 hours [(17.02％ ± 4.85％,17.48％ ± 4.04％,respectively,P＜0.05 or P＜0.01].After transfection,compared with blank vector group,the apoptosis of SESN2 siRNA group obviously elevated [(65.96％ ± 2.50％) vs.(50.01％ ± 2.07％),P＜0.05],and cleaved-caspase-3 expression significantly increased while Bcl-2 expression obviously decreased.In SESN2 LV-RNA group,the apoptosis significantly decreased [(35.57％ ± 1.69％) vs.(49.04％ ± 4.87％),P＜0.05],and cleaved-caspase-3 expression decreased and Bcl-2 expression obviously increased compared with blank vector group (P＜0.05).Conclusion SESN2 has a protective effect against HMGB 1 induced apoptosis of D C2.4 cells.