Figure 2. Sirt1 inhibits 9G8-enhanced 3R-tau expression. (A) 9G8 or Sirt1 was overexpressed individually or together into HEK-293T cells transfected with mini-tau gene pCI/SI9-SI10 for 48 h. The splicing products of tau exon 10 were analyzed by RT-PCR. (B) Mini-tau gene was co-transfected into HEK-293T cells with siRNA of Sirt1 only or together with 9G8, and then splicing products were analyzed by RT-PCR 48 h after transfection. (C) pcDNA3.1/SIRT1 or pcDNA/3.1H363Y was transfected only or together with 9G8 into HEK-293T cells. Splicing products were analyzed by RT-PCR after 48 h transfection. The ratios of tau exon 10 inclusion to exclusion are presented as mean ± S.D. and analyzed with two-way ANOVA. *, p < 0.05, **, p < 0.01, ***, p < 0.001, compared with control group; ## p < 0.01, compared with 9G8 group.