Figure 5 SIRT1 silencing decreased the viability and increased cell apoptosis in OGD-induced primary rat neuronal cells. Primary rat neuronal cells were transfected with SIRT1-siRNA or control-siRNA for 48 h, then the cells were treated with OGD for 48 h. (A) Cell viability was determined by MTT assay. (B, C) Cell apoptosis was determined by flow cytometry. (D) Bax and Bcl-2 protein levels were determined by Western blot assay. Control: cells without any treatment; OGD: cells were subjected to OGD treatment; OGD+control-siRNA: cells were transfected with control-siRNA and then subjected to OGD treatment; OGD+SIRT1-siRNA: cells were transfected with SIRT1-siRNA and then subjected to OGD treatment. The results are presented as the mean±SD. ** P<0.01 vs. control group; ## P<0.01 vs. OGD group. OGD – oxygen and glucose deprivation; SIRT1 – sirtuin-1.