Skin Surface Properties & the interplay with the Environment

Molecular cartography of the human skin surface in 3D. A. Bouslimani, et al. Proc Natl Acad Sci U S A. 2015 Apr 28;112(17):E2120-9. doi: 10.1073/pnas.1424409112. Epub 2015 Mar 30. Full free article: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4418856/

GOAL
In this article the authors sought to evaluate the biochemical properties of the skin by performing swabs on 400 sites (of 2 volunteers):
-One swab was used to define the microbiome of the germs present (16S ribosomal RNA amplicon analysis)
-One swab was used to check the skin composition: metabolite, lipid, and protein composition (mass spectrometry (MS))

RESULTS
A huge number of data was gathered but the authors:
-managed to determine the origin of the skin composition: environmental (cosmetics…), microbial, or cutaneous
-as well as the expected 3d organization of the molecules and germs bacteria which were present.

-The properties varied vastly between the areas sampled and between the 2 volunteers.
-8% of chemical substances were cosmetics or beauty products. They were present despite the subjects having washed thoroughly 3 days before.

LIMITATIONS
-The study was limited by a limited pre-existing MS library which could only match with 3% of findings.

CONCLUSION
In a short conclusion: Biochemical Skin Surface Properties are the result of the interaction with the environment determined by microbes and cosmetics !
The “LIMITATIONS” show that this is only the beginning of the exploration of a fundamental understanding of the biochemical properties of the skin.

COMMENTS
-What is interesting is that the possibility to control environmental factors (or not) is important in determining the biochemical properties of the skin and in the end its appearance (pathological or not).
-One of the environmental factors we can control is the cosmetics and topicals that we apply on the skin. (Apparently washing does NOT remove them !)
-Understanding skin diseases might be greatly advanced by the understanding of its molecular properties.

Article selection: Prof Dr Jean-Hilaire Saurat – dermatologist. Geneva, Switzerland