FIGURE 8.

p300-mediated enrichment of H3K27ac at the Runx2 P1 promoter accompanies Runx2 expression in osteoblasts. C2C12 cells were infected with lentiviral particles coding for shRNAs against p300 or control (E.V.) for 72 h and then differentiated to the osteoblast lineage as described earlier. A, P300 knockdown was confirmed by Western blot using specific antibodies. Detection of RNA Pol II was used to control for equal loading. B, Runx2-II/p57 mRNA levels were measured by qRT-PCR 72h after infection (and 48 h of differentiation) and normalized against GAPDH. C, chromatin samples were analyzed by ChIP using an antibody against H3K27ac. Results are expressed as % input ± S.E., and normal IgG was used as specificity control. Statistical analyses were performed with respect to the cells infected with virus generated with the pLKO.1 empty vector (E.V). *, p < 0.05.