Protection role of silent information regulator 1 in toxicity of activated BV-2 cells to PC12 cells / 中华神经医学杂志

ABSTRACT

Objective To observe the effects of silent information regulator 1 (SIRT1) on toxicity of activated BV-2 to PC12 cells and the possible mechanisms.Methods BV-2 microglial cells and PC12 cells were routinely cultured in vitro; ELISA was used to measure to the levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) stimulated by lipopolysaccharide (LPS,1 μg/mL) in BV-2 cells.MTT assay was employed to identify the cell viability of PC12 cells injured by culture medium of activated BV-2 and determined the suitable concentrations of resveratrol (a potent SIRT1 activator,5,10,25,50 and 100 μmol/L) and nicotinamide (a known SIRT1 inhibitor,5,10,25 and 50 mmol/L).PC12 cells were divided into groups as follows:control group Ⅱ,LPS+BV-2 co-cultured group,resveratrol treatment group and nicotinamide treatment group (pretreated with resveratrol or nicotinamide for 2 h,and then subjected to culture medium of activated BV-2 cells,in the presence of resveratrol or sirtinol for 18 h); the cell viability was measured by OD value in MTT assay,and the expressions of SIRT1 and acetyl-p53 were detected by Western blotting.Results TNF-α and IL-6 secretions increased gradually at 6,12 and 24 h after LPS being induced BV-2,with significant difference between each two time points (P＜0.05).PC12 cell viability decreased in the LPS+BV-2 co-cultured group as compared with that in the control group Ⅰ,LPS treatment group and BV-2 supernate group (P＜0.05).The cell viability of cells in the 100 μmol/L resveratrol treatment group and 50 μmol/L niacinamide treatment group decreased as compared with that in the control group Ⅱ (P＜0.05),therefore,50 μmol/L resveratrol and 25 μmol/L nicotinamide were chosen in the next experiment.As compared with those in the control group Ⅲ,the cell viability and SIRT1 expression significantly decreased,and acetyl-p53expression significantly increased in the LPS+BV-2 co-cultured group (P＜0.05); as compared with those in the in the LPS+BV-2 co-cultured group,the cell viability and SIRT1 expression significantly increased,and acetyl-p53 expression significantly decreased in the 50 μmol/L resveratrol treatment group,and opposite results were noted in the 25 μmol/L nicotinamide treatment group (P＜0.05).Conclusion SIRT1 can inhibit toxicity of activated BV-2 to PC12 cells,the mechanism of which is partly via p53 activation.