Surface Ultra-Structure and Size of Human Corneocytes from Upper Stratum Corneum Layers of Normal and Diabetic Subjects with Discussion of Cohesion Aspects

Markus Stucker Michael Licht,H Michael Heise

doi:10.4172/2155-6156.1000603

Abstract

Background: During the final stage of differentiation of cornified squamous epithelia like the human skin epidermis, anucleated corneocytes are formed. Formation of the horny layer and its ongoing desquamation are fundamental processes leading to the formation of an efficient epidermal barrier. Materials and methods: For a better understanding of the desquamation process, the role of corneocyte surface ultra-structure has been investigated using a special preparation technique for scanning electron microscopy (SEM). Human morphologically different corneocytes from the stratum corneum of the fingertip, the thenar eminence (thick skin), and the wrist below the carpus (thin skin) of normal and diabetic subjects were obtained by adhesive tape stripping. Results: The inside surface structure of corneocytes from thick skin shows prominent nubs, which are broader and more extended than those of thin skin. Towards their outside, corneocytes were flat with cavities as indentations of the nubs from neighboured cells providing clues on the mechanical strength of the ‘intercellular stickiness’. As the size of thin skin corneocytes for diabetic subjects was also studied, it was found that their area was slightly nonlinearly dependent on age. Conclusion: Accordingly to a reduced proliferation and differentiation rate, as postulated for diabetic persons, differences in size were as expected but statistically not significant, compared with corneocytes under normal homeostasis conditions. For discussion is a model, for which the interwoven cellular connectivity provides additional mechanical strength for the stratum corneum in thick skin.

Highlights

The stratum corneum (SC) is composed of keratinocytes at different stages, joined together with corneodesmosomes, embedded in a hydrophobic lipid matrix
Formation of the horny layer and its ongoing desquamation, i.e. the shedding of superficial corneocytes from the skin surface, are fundamental processes leading to the establishment of an efficient epidermal barrier
It is obvious that the outside corneocyte surface is rather smooth, aside from some indentations

Summary

Introduction

The stratum corneum (SC) is composed of keratinocytes at different stages, joined together with corneodesmosomes, embedded in a hydrophobic lipid matrix. During the final stage of differentiation of cornified squamous epithelia, such as the skin epidermis, anucleated corneocytes are formed. Formation of the horny layer and its ongoing desquamation, i.e. the shedding of superficial corneocytes from the skin surface, are fundamental processes leading to the establishment of an efficient epidermal barrier. The stratum corneum can be shedded into single squames in different ways; these include mechanical desquamation as well as the use of agents such as detergents and enzymes. During the final stage of differentiation of cornified squamous epithelia like the human skin epidermis, anucleated corneocytes are formed. Formation of the horny layer and its ongoing desquamation are fundamental processes leading to the formation of an efficient epidermal barrier

Methods

Results

Discussion

Conclusion