Fig. 8.

Electron microscopy of skin, lung, and aorta of control and Neu1-null littermates. In the skin of Neu1-null mice (top, right), the scarce elastic fibers look highly immature. They mostly consist of parallel-oriented microfibrils, lightly decorated with single patches, electron-dense elastin (arrows). These immature fibers differ from the well-developed counterparts containing the electron-dense core (arrows) made of cross-linked elastin embedding the microfibrillar scaffold (top, left). In contrast to well-developed elastic fibers (containing electron-dense elastin) seen in the lungs of control mice (middle, left), lungs of Neu1-null mice (middle, right) demonstrate scarce, thin, and fragmented elastic fibers deposited by the vacuolated fibroblasts or smooth muscle cells (SMCs) (middle, right). The aortic wall of the Neu1-deficient mice (bottom, right) show grossly abnormal organization of vacuolated SMCs coinciding with the presence of thinner and irregularly shaped elastic laminae that contained remarkably less electron-dense elastin than aortas of the age-matched control mice (bottom, left).