Fig. 5: AMPK regulates ARF1-mediated contact of LDs with mitochondria.

A Immunoprecipitation using an anti-EGFP antibody and immunoblotting with the same antibody. Cells transfected with Plin2-mCherry and ARF1-EGFP expression vectors were treated or not with BAY-3827 (5 μM, 8 h) under glucose-fed or glucose-starved conditions (n = 3). B, C Representative optical section images and quantitative analysis of LD-mitochondrion contacts in C2C12 cells immunostained with MitoTracker (mitochondrial marker, purple) and LipidTOX (LD marker, yellow). Cells were treated with or without BAY-3827 for 8 hours under glucose starvation conditions (n = 30). Scale bar, 10 μm. D, E Quantification of the number (n = 30) and area (n = 30) of LDs per cell. F, G Representative optical section images and quantification results of ARF1 and LD contacts in C2C12 cells immunostained with ARF1 antibody (green) and LipidTOX (LD marker, green). Cells were treated with or without BAY-3827 for 8 hours under glucose starvation conditions (n = 30). Scale bar, 10 μm. H, I Representative optical section images and quantification results of ARF1 and mitochondrial contacts in C2C12 cells immunostained with ARF1 antibody (light blue-green) and MitoTracker (mitochondrial marker, purple). Cells were treated with or without BAY-3827 for 8 h under glucose starvation conditions (n = 30). Scale bar, 10 μm. C–E, G, I Data are presented as means ± SD of three biologically independent replicates, analyzed by two-sided unpaired Student’s t-test. *p < 0.05, **p < 0.01, ***p < 0.001.