Nanostructure of the epidermal extracellular space as observed by cryo-electron microscopy of vitreous sections of human skin

Abstract

The newly developed method, cryo-electron microscopy of vitreous sections, was used to observe the nanostructure of the epidermal extracellular space. The data were obtained from vitreous sections of freshly taken, fully hydrated, non-cryo-protected human skin. The extracellular space of viable epidermis contains desmosomes, expressing a characteristic extracellular transverse ∼ 5 nm periodicity, interconnected by a relatively electron lucent inter-desmosomal space. The extracellular space between viable and cornified epidermis contains transition desmosomes at different stages of reorganization interconnected by widened areas expressing a rich variety of complex membrane-like structures. The extracellular space of cornified epidermis contains ∼ 9, ∼ 14, ∼ 25, ∼ 33, ∼ 39, ∼ 44, and ∼ 48 nm thick regions in turn containing one, two, four, six, eight, eight, and ten parallel electron-dense lines, respectively, between adjacent corneocyte lipid envelopes. The eight-line ∼ 44 nm thick regions are most prevalent. Copyright © 2005 by The Society for Investigative Dermatology, Inc.