Figure 4.

Insulin blocks loss of mitochondrial depolarization. hTCEpi cells were cultured for 48 h in KGM or KBM with or without 5 μg/ml of insulin. Mitochondria were stained with MitoTracker green (MTG, green), a marker of mitochondrial morphology, and TMRE (red), a marker for polarized mitochondria. Culture in basal media without growth factor supplements resulted in mitochondrial depolarization and fragmentation. Concurrent treatment with insulin blocked depolarization and stimulated mitochondrial elongation. KGM, keratinocyte growth media; KBM, keratinocyte basal media; INS, insulin; hTCEpi cells, human telomerized corneal epithelial cells. Scale bar: 5 μm. Adapted from Titone et al. (34).