Figure 3.

Pretreatment of MCF7 cells with NAD+ prevents the enlargement of mitochondria and protects mitochondria from losing membrane potential caused by metformin. MCF7 cells were pretreated with NAD+ (1 mM) for 3 days and then treated with or without metformin for 2 days. (A) Phase contrast image of MCF7 cells. (B) MCF7 stable cells expressing pAcGFP1-Mito Vector were visualized using confocal microscopy to see the morphology of the mitochondria. (C) Cells were stained using TMRE. Flow cytometry was used to detect the change of mitochondrial membrane potential.