Figure 1.

Parp1 and PARylation activity in the pluripotent or differentiated state. (A) Morphology and staining for ALP and SSEA-1 in Re-7 iPSCs. BF, bright field. Bars, 100 µm. Nuclear proteins from Re-7 iPSCs and MEFs were separated into five fractions by 1D-DIGE. (B) Pie chart showing the GO classification of gene functions in all nuclear proteins from iPSCs. (C) Expression of Oct4, Nanog, c-Myc, Parp1, and PARylation activity in pluripotent stem cells, including ESCs and iPSCs transfected with OSKM or OSK. (D, top) Expression of the pluripotency factors Oct4, Sox2, Klf4, c-Myc, and Parp1. (D, bottom) PARylation activity during the reprogramming process. (E) Parp1 expression and PARylation activity in EBs 6 d after differentiation. (F, left) Differentiation of Re-7 iPSCs into osteocyte-like, hepatocyte-like or neuron-like cells, confirmed by positive staining with Alizarin red, PAS, and the neuron-specific markers Nestin and MAP2, respectively. Bars, 100 µm. (F, right) Detection of Parp1, Parp2, TopII-α, Oct4, Sox2, and Klf4 proteins in Re-7 iPSCs, before and after differentiation into the indicated specific lineages. The Western blots are representative of three separate experiments with independent cell preparations.