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Cultivating a Three-dimensional Reconstructed Human Epidermis at a Large Scale
Published on: May 28, 2021
Tight junctions in the stratum corneum explain spatial differences in corneodesmosome degradation
Satomi Igawa1, Mari Kishibe, Masamoto Murakami
1Department of Dermatology, Asahikawa Medical College, Asahikawa, Japan.
Experimental Dermatology
|October 20, 2010
Summary
Tight junctions (TJs) in the stratum corneum create a barrier, preventing proteases from degrading corneodesmosomes centrally. This maintains skin barrier function and controlled desquamation.
Area of Science:
- Dermatology
- Cell Biology
- Skin Physiology
Background:
- Stratum corneum integrity relies on controlled corneodesmosome degradation for desquamation.
- The peripheral localization of corneodesmosomes in upper stratum corneum remains unexplained.
- Understanding this localization is key to skin barrier function and homeostasis.
Purpose of the Study:
- To investigate the distribution of key corneodesmosomal components in human epidermis.
- To elucidate the structural basis for the peripheral localization of corneodesmosomes.
- To test the hypothesis that tight junctions (TJs) regulate protease access in the stratum corneum.
Main Methods:
- Immunofluorescent microscopy of skin surface corneocytes.
- Immunoelectron microscopy to analyze component distribution.
- Colloidal lanthanum nitrate perfusion assay on stripped stratum corneum.
Main Results:
- Corneodesmosin, desmoglein 1, and desmocollin 1 were localized to cell edges in corneocytes.
- Selective loss of these components occurred centrally in deeper cornified layers.
- Tight junctions were observed up to the seventh/eighth cornified layers, excluding protease tracers.
Conclusions:
- Tight junctions act as barriers, restricting protease access to peripheral corneodesmosomes.
- This TJ-mediated protease restriction explains the peripheral corneodesmosome distribution.
- The findings provide a structural basis for the stratum corneum's basket-weave appearance and controlled desquamation.
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