Long-Term IGF-I Exposure Decreases Autophagy and Cell Viability (original) (raw)
Figure 2
IGF-I treatment increases mitochondrial depolarization.
WI-38 fibroblasts were maintained for 14 days in MCDB 105 medium, MCDB 105 medium with IGF-I (40 ng/ml), or MCDB 105 medium with EGF (40 ng/ml). Medium with or without growth factors was replenished every 3 days and cells were stained for mitochondrial potential at that time as described in materials and methods. Cells with depolarized mitochondria were visualized by flow cytometry as described in Material and Methods. A. Percentage of cells with depolarized mitochondria as assessed by JC-1 staining (*, P<0.001). B. Representative dot blot of JC-1-stained cultures in MCDB 105 with or without IGF-I or EGF. Y-axis, fluorescence at 590 nm; X-axis, fluorescence at 525 nm. A downward shift on the X-axis is indicative of mitochondrial membrane depolarization.