Fig. 2: Insulin receptor bodies in HepG2 cells.

a Schematic of cell treatments (top). Representative immunofluorescence images of IR (green) in cells stimulated with (3 nM) or without (0 nM) insulin for 5 min (bottom). Dashed light blue lines represent the outline of the nucleus. Orange, magenta, and yellow boxes represent regions at the plasma membrane (PM), nucleus, and cytoplasm (Cytop), respectively, that are magnified (ZOOM, middle). Scale bars are indicated. b Quantification of IR signal intensity in puncta at the plasma membrane (top), cytoplasm (middle), and nucleus (bottom) in insulin-sensitive cells stimulated (3 nM, blue) or not (0 nM, light blue) with insulin and in insulin-resistant cells stimulated (3 nM, dark red) or not (0 nM, red) with insulin. Data are represented as mean + /− SEM. The number of puncta analyzed: sensitive 0 nM insulin plasma membrane 342 puncta, cytoplasm 366 puncta, nucleus 48 puncta; sensitive 3 nM insulin plasma membrane 272 puncta, cytoplasm 378 puncta, nucleus 23 puncta; resistant 0 nM insulin plasma membrane 406 puncta, cytoplasm 295 puncta, nucleus 31 puncta; resistant 3 nM insulin plasma membrane 328 puncta, cytoplasm 283 puncta, nucleus 69 puncta. Unpaired two-sided t test was used for statistical analysis. c Schematic of cell treatments to model insulin resistance (top). Representative immunofluorescence images for IR (green) in insulin-resistant cells acutely stimulated with (3 nM) or without (0 nM) insulin (bottom). Orange, magenta, and yellow boxes represent regions at the plasma membrane (PM), nucleus, and cytoplasm (Cytop), respectively, that are magnified (ZOOM, middle). Scale bars are indicated. d Schematic of cell treatments (top). Cells expressing endogenous IR tagged with GFP (IR-GFP) were used. Metformin concentration used is 12.5 μM. Representative images for IR-GFP in insulin-sensitive, insulin-resistant, and metformin-treated insulin-resistant cells stimulated with insulin (3 nM) for 5 min (bottom). Orange, magenta, and yellow boxes represent regions at the plasma membrane (PM), cytoplasm (Cytop) and nucleus, respectively, that are magnified (ZOOM). Scale bars are indicated. e Quantification of IR-GFP signal intensity in IR puncta at the plasma membrane, cytoplasm, and nucleus of insulin-sensitive (blue), insulin-resistant (red) and metformin-treated insulin-resistant (purple) cells acutely stimulated with (3 nM) insulin. Data are represented as mean + /− SEM. The number of puncta analyzed: sensitive 3 nM insulin plasma membrane 60 puncta, cytoplasm 59 puncta, nucleus 45 puncta; resistant 3 nM insulin plasma membrane 90 puncta, cytoplasm 90 puncta, nucleus 65 puncta; resistant metformin 3 nM insulin plasma membrane 82 puncta, cytoplasm 41 puncta, nucleus 67 puncta. Unpaired two-sided t test was used for statistical analysis. Source data are provided as a Source Data file.