Figure 2
Enhanced autophagy in T2D. (A) Autophagosome-related structures visualized in thin sections of adipocytes by transmission electron microscopy; ap, autophagosome; cLD, central lipid droplet; LD, cytosolic lipid droplet; pm, plasma membrane; cav, caveolae. (B) Number of autophagosome-related structures in adipocytes from five nondiabetic (open bar; age 49–76, average 63.6 years; BMI 26.7–34.9, average 29.1 kg/m2) and five diabetic (filled bar; age 32–63, average 46.6 years; BMI 37.2–45.4, average 40.9 kg/m2) subjects determined by transmission electron microscopy of thin sections of five different whole cells from each subject. Results are given as number of autophagosome-related structures per whole-cell thin-section, mean ± SE. (C) Immunofluorescence confocal microscopy of nondiabetic (left) and diabetic (right) adipocytes that were incubated with 50 nmol/L rapamycin and 5 µmol/L chloroquine for 18 h, when LC3 was detected. (D) Autophagic activity, amount and turnover of particulate LC3. Adipocytes were isolated from seven nondiabetic subjects (open bars; age 28–85, average 53.3 years; BMI 19–35, average 26.1 kg/m2) and seven patients with T2D (filled bars; age 32–69, average 48.4 years; BMI 29–45.4, average 39.5 kg/m2) and incubated, with or without rapamycin and chloroquine, as in (C), when LC3 was determined by immunofluorescence microscopy. We analyzed 20 randomly selected cells per subject and condition. Results are given as fluorescence per imaged area of the cells, mean ± SE.