The Role of Oxidative Stress and Autophagy in Atherosclerosis

Figure 2

Transmission electron micrographs of atherosclerotic human aorta. Synthetic SMCs undergoing autophagy (a). Autophagic vesicles (arrowheads) generally possess a high electron density. The cytoplasmic material targeted for autophagic destruction is sequestered into a double or multilayered membranes vesicle called autophagosomes (asterisks in b, c, and d). Lipid droplets (L) are clearly distinguishable from the autophagic vesicles by virtue of their homogeneous gray appearance. Autophagosomes fuse with lysosomes (ly) and their cargo is degraded and recycled. Lysosomes usually appear as small electron-dense, single-membrane spherical vacuoles (c). The black arrow indicates an endosome; m: mitochondria (d).