A. Validation of siRNAs directed against Pik3cb. NRVMs were transfected with the indicated siRNAs. After 2 days, Pik3cb mRNA was measured by qRT-PCR. NC, negative control. B-E. Effect of Pik3cb knockdown on YAP-stimulated NRVM proliferation. P4 NRVMs were treated with control (NC) or Pik3cb siRNA and adenovirus expressing LacZ (L) or YAP (Y). Proliferation was measured 1 day later by BrdU uptake (B,C) or pH3 staining (D,E). Dashed rectangles indicate areas enlarged in insets. Arrows and arrowheads indicate positive cardiomyocytes and non-myocytes, respectively. Bar = 50 μm (B) or 100 μm (D). *, P<0.05. n=3.