FIG. 6.

Statins promote mitophagy. (A) Representative images of Parkin translocation to the mitochondria of HL-1 cells given DMSO or 1 μM simvastatin with or without concomitant supplementation with 5 μM coenzyme Q₁₀ for 24 h. Parkin (red) and Tom70 (green) were immunolabeled, and nuclei were stained with Hoeschst33432. To emphasize mitochondrial translocation of Parkin, processed images were thresholded for yellow color representing colocalized points (Parkin and Tom70). The Pearson's correlation coefficient (R) was used to assess colocalization indicated in representative images. (B) HL-1 cells treated as in (A) were scored for Parkin translocation to the mitochondria. Cells exhibiting more than 40% colocalization of Parkin to mitochondria were counted as positive. n=4 plates per group. *p-value<0.05. (C) Mitochondrial interconnectivity was examined to assess mitochondrial fragmentation versus network morphology. The oval signifies fused mitochondria (high connectivity ratio) and the two small spheres signify mitochondrial fragmentation (low connectivity ratio). (D) Determination of mitophagy defined by the loss of Tom70 fluorescence per unit cell area. Perimeters of individual cells were outlined as in the sample image and quantified for fluorescence intensity of Tom70. n=4 per group; at least 100 cells were analyzed per n. *p-value<0.05. Treatment groups identified as: vehicle (DMSO, solid bars) and simvastatin (statin, hashed bars).