Glycan distribution and density in native skin's stratum corneum

Area of Science:

• Biophysics
• Biochemistry
• Dermatology

Background:

• Glycosylation of corneocyte surface proteins is vital for stratum corneum (SC) cellular adhesion.
• Traditional methods like immunohistochemistry and electron microscopy lack resolution or require high vacuum for glycan mapping.
• Accurate localization of glycans is challenging in native skin conditions.

Purpose of the Study:

• To investigate the distribution of glycans on native human stratum corneum (SC) corneocytes.
• To map glycan localization with high resolution without chemical preparation.
• To observe glycan presence and degradation in their native state.

Main Methods:

• Utilized advanced atomic force microscopy (AFM) with simultaneous topography and recognition imaging.
• Employed AFM cantilever tips functionalized with anti-heparan sulfate antibody and wheat germ agglutinin (WGA) lectin.
• Analyzed native, non-chemically prepared, stripped human SC samples.

Main Results:

• Observed heparan sulfate and WGA-binding glycans on the SC corneocyte surface in native conditions.
• Identified glycans associated with bead-like domains representing corneodesmosomes.
• Quantified a significant decrease in glycan density from lower SC layers (~1200 molecules/μm²) to the surface (~106 molecules/μm²), suggesting corneodesmosome degradation.

Conclusions:

• First observation of glycan spatial distribution and degradation on the SC surface in native conditions at high resolution.
• The developed AFM method allows precise localization of macromolecules on skin surfaces.
• This technique is extendable to other tissues requiring analysis in their native state.