Fig. 2

iPSCs exhibit higher autophagy activity than parental fibroblasts. Fibroblasts (a–d, a′–d′) and iPSCs (A–D, A′–D′) derived from four independent donors were cultured in the absence (–R) or presence (+R) of 100 nM rapamycin for 24 hours. iPSCs showed higher basal staining of LC3B (A–D) than in parental fibroblasts (a–d). LC3B was highly induced by 100 nM of rapamycin in iPSCs (A′–D′), with lower levels of induction in their respective fibroblasts (a′–d′). Fluorescent images were acquired via confocal microscopy. Bar = 10 μm. (E) Immunoblots of the protein extracts from untreated (–R) or treated (+R) cells with anti-LC3B-II and anti-β-ACTIN. (F, G) The relative abundance of LC3B-II was quantified using ImageJ software and data were presented as mean ± SD. (F) The basal level of LC3B-II in the iPSCs was 2.55-fold higher than in parental fibroblasts (**p < 0.01, n = 4). (G) Rapamycin-induced expression of LC3B-II in the iPSCs was also 2.23-fold higher than fibroblasts (*p < 0.05, n = 4). Fib fibroblasts, iPSC induced pluripotent stem cell