Increased number of lipid droplets in T2D. (A) Lipid droplets (LD) visualized by transmission electron microscopy. Left, parts of three cells are seen; in the leftmost cell there are small lipid droplets in the cytosol separate from the central lipid droplet (cLD). LD-patch, patch of cytosolic lipid droplets; pm, plasma membrane; ecm, extracellular matrix. (B) Amount of cytosolic lipid droplets (>100 nm) in adipocytes from five nondiabetic subjects (open bar; age 49–76, average 63.6 years; BMI 26.7–34.9, average 29.1 kg/m2) and five diabetic patients (filled bar; age 32–63, average 46.6 years; BMI 37.2–45.4, average 40.9 kg/m2) determined by transmission electron microscopy of thin sections of five different whole cells from each subject, as described in Experimental Procedures. Results are given as number of cytosolic droplets per whole-cell thin section, mean ± SE. (C) Autophagy of lipid droplets visualized by immunofluorescence confocal microscopy. Adipocytes were incubated with 50 nmol/L rapamycin and 5 µmol/L chloroquine for 18 h, when cells were incubated with antibodies against perilipin (red) and LC3 (green). Confocal section close to the plasma membrane shown. LD-patch, patch of cytosolic lipid droplets. (D) Autophagy of lipid droplets visualized by transmission electron microscopy; ap, autophagosome with lipid droplets; LD, lipid droplets; cLD, central lipid droplet; pm, plasma membrane.