The optimal concentration of siRNA for gene silencing in primary cultured astrocytes and microglial cells of XXXX .

@entity35 @entity137 @entity149 @entity941
BACKGROUND: Small interfering RNAs (siRNAs) have been used to knockdown specific gene expression in various cells. Astrocytes and microglial cells play a key @entity149 . The aims of this study were to determine the optimal concentration of siRNA demonstrating efficient transfection and inhibition of gene expression via RNA interference (RNAi) and lower @entity137 , in primary cultured astrocytes and microglial cells of @entity35 . METHODS: Astrocytes and microglial cells were isolated from the cerebral cortices of 2-day-old @entity35 . Both the cells were transfected using transfection reagent (Lipofectamine    2000), and @entity941 -labeled double-stranded RNA (dsRNA) or siRNA targeting green fluorescent protein. Transfection efficiency and @entity137 of dsRNA, and the degrees of RNAi induced by siRNA in these cells, were evaluated at various concentrations of RNA. RESULTS: Transfection efficiencies of dsRNA in both astrocytes and microglial cells were significantly higher (P < 0.05) at the concentrations of 20, 40, and 80 nM than at the concentrations of 0, 5, and 10 nM. There were no significant cytotoxicities within the applied concentrations of dsRNA (0-80 nM). The degrees of RNAi induced by siRNA were significantly higher (P < 0.05) at the concentrations of 5, 10, 20, 40, 80 nM, and 20, 40, 80 nM in astrocytes and microglial cells, respectively, compared with the control (0 nM). CONCLUSIONS: The siRNA concentration of 20 nM may be appropriate to induce RNAi in both astrocytes and microglial cells, while demonstrating low @entity137 , high transfection efficiency, and effective RNAi.
