Figure 6. SIRT1 protein levels are upregulated during reprogramming.. (A) mESCs, MEFs, and iPS cells were subject to western blot analysis with antibodies to the indicated proteins. (B) SIRT1, HDAC1, and HDAC2 protein levels relative to tubulin were quantified by densitometry. (C) qRT-PCR analysis of SIRT1 mRNA levels in mESCs, MEFs, and iPS cells were measured relative to GAPDH. (D) qRT-PCR analysis of miRNA expression relative to miR-16 in mESCs, MEFs, and iPS. Data are mean ± s.d. for three samples.