Fig. 8. Survivin RNAi blunts DADLE-induced protection of cardiomyocytes against apoptosis. (A) Representative micrographs and (B) percentage of apoptotic cells as assessed by TUNEL staining. In cardiomyocytes cultured under DEPV conditions, survivin RNAi increased apoptosis in the absence or presence of DADLE. However, survivin RNAi did not change the number of apoptotic cardiomyocytes cultured under control condition. (C) Survivin siRNA blunted the effect of DADLE in reducing apoptosis of cardiomyocytes cultured under DEPV conditions. There was a survivin RNAi-induced increase in the number of apoptotic cardiomyocytes cultured under DEPV conditions as compared with that of the non-transfected or the GAPDH RNAi group in either the absence or the presence of DADLE (A,B). However, survivin RNAi did not change the number of apoptotic cardiomyocytes cultured under control condition. DADLE-induced reduction in the cardiomyocytes transfected with survivin siRNA was significantly less than that in the non-transfected cardiomyocytes or those transfected with GAPDH siRNA (C). Values are the mean ± s.d. ^*P<0.05. n=6 in each group. DEPV, serum and glucose deprivation; DADLE, [D-Ala2, D-Leu5]-enkephalin acetate salt; RNAi, RNA interference; siRNA, small interfering RNA; TUNEL, TdT-mediated dUTP nick end labeling.