Fig. 7. Survivin RNAi abrogates DADLE-induced increase in survivin expression in cardiomyocytes. (A) Survivin expression, identified by immunofluorescent staining, was significantly decreased by transfection of survivin siRNA in cultured cardiomyocytes (red signals for survivin). Successful transfection was confirmed by the green signals of GFP labeling conjugated with the siRNAs. Micrographs are representative of four independent experiments. (B) 48 hours after transfection, mRNA transcripts of survivin as measured by real-time RT-PCR were significantly reduced by survivin RNAi in cardiomyocytes cultured under control condition, as well as in cardiomyocytes cultured under DEPV conditions with or without DADLE treatment. (C) Representative blots and quantification of survivin levels by densitometry. DADLE-induced increase in survivin levels was abrogated by transfection of survivin RNAi 72 hours after transfection. Transfection of survivin siRNA and GAPDH siRNA specifically knocked down the expression of their respective target genes without affecting each other's targets. Values are the mean ± s.d., n=6. ^*P<0.05. DADLE, [D-Ala2, D-Leu5]-enkephalin acetate salt; DEPV, serum and glucose deprivation; RNAi, RNA interference; siRNA, small interfering RNA.