Figure 2. Effect of growth factor re-addition on the nuclear localization of GAPDH after serum depletion of senescent HDFs. (A) Subconfluent senescent HDFs were serum-depleted by incubation in SFM for 5 days. PDGF (100 ng/ml) or LPA (30 μM) was then added to the serum-depleted cells for 2 days. Cells were immunostained against GAPDH and analyzed by confocal laser scanning microscopy. Immunostained cells with re-addition of PDGF or LPA are shown in A (×100 with 50 μm scale bar). (B and C) After the re-addition of PDGF (B) or LPA (C) for the indicated times (1–48 h), the number of cells with cytosolic GAPDH alone (Cytosol) and cells having nuclear GAPDH with or without cytosolic GAPDH (Nuclear +/− Cytosol) was counted, and the percentage distributions were calculated (n = 8 for total replicates) and plotted as means ± standard deviations. ***p < 0.001 (Cytosol) and ###p < 0.001 (Nuclear +/− Cytosol), compared with vehicle-treated control SFM-5d cells.