The role of the corneocyte lipid envelopes in cohesion of the stratum corneum.
Treatment of isolated stratum corneum with certain detergents results in complete disaggregation of the corneocytes within hours at 45 degrees C without agitation. This is prevented by prior heating of the tissue to 80 degrees C or by solvent extraction of the intercellular lipids. In the present study, electron microscopy revealed that the heated or solvent-extracted tissue was characterized by cell-to-cell contacts that appeared to involve the chemically bound hydroxyceramides which constitute the corneocyte lipid envelope. It is proposed that the irreversible bonding between corneocytes that results from heating or lipid extraction results from interdigitation of the sphingosine chains belonging to those hydroxyceramides that are bound to the corneocyte protein envelope by the omega-hydroxyl function of the 30- and 32-carbon hydroxyacid moieties. Similar interdigitation of adjacent envelopes might be involved in natural stratum corneum cohesion, limited mostly to the periphery of corneocytes where the absence of intercellular lamellae allows the appropriate cell-to-cell contact.
Wertz
P W
PW
Department of Dermatology, University of Iowa College of Medicine, Iowa City 52242.
Swartzendruber
D C
DC
Kitko
D J
DJ
Madison
K C
KC
Downing
D T
DT
D000818:Animals; D002449:Cell Aggregation / Q000187:drug effects; D002725:Chloroform / Q000494:pharmacology; D003902:Detergents / Q000494:pharmacology; D006358:Hot Temperature; D008055:Lipids / Q000502:physiology*; D000432:Methanol / Q000494:pharmacology; D008854:Microscopy, Electron; D008968:Molecular Conformation; D012867:Skin / Q000166:cytology / Q000648:ultrastructure; D012879:Skin Physiological Phenomena; D012997:Solvents / Q000494:pharmacology; D013552:Swine
D003902:Detergents; D008055:Lipids; D012997:Solvents; D002725:Chloroform; D000432:Methanol