Effects of SIRT1 modulators in GGA-induced increase on SAP97 mRNA. HL-1 cells treated with the SIRT1 activator resveratol (50 µM), in (A) or the SIRT1 inhibitor nicotinamide (5 mM) overnight, in (B) after stimulation with GGA (100 nM) overnight, and real-time PCR analysis was performed with SAP97 and β-actin primers. The mean ratio (±SEM) of SAP97 mRNA quantity normalized to β-actin (n = 6 for control and each treatment groups) is shown. Statistical significance of the differences among each group was tested by Student's t-test: *P < 0.05, **P < 0.01. GGA, geranylgeranylacetone; PCR, polymerase chain reaction.